Effect of intraluminal thrombus on abdominal aortic aneurysm wall stress

PURPOSE: Abdominal aortic aneurysms (AAAs) rupture when the wall stress exceeds the strength of the vascular tissue. Intraluminal thrombus may absorb tension and reduce AAA wall stress. This study was performed to test the hypothesis that intraluminal thrombus can significantly reduce AAA wall stress. METHODS: AAA wall stresses were determined by axisymmetric finite element analysis. Model AAAs had external diameters ranging from 2.0 to 4.0 cm. Model parameters included: AAA length, 6 cm; wall thickness, 1.5 mm; Poisson's ratio, 0.49; Young's modulus, 1.0 MPa; and luminal pressure, 1.6 x 10(5) dyne/cm2. Stresses were calculated for each model without thrombus, and then were recalculated with thrombus filling 10% of the AAA cavity. Calculations were repeated as thrombus size was increased in 10% increments and as thrombus elastic modulus increased from 0.01 MPa to 1.0 MPa. Maximum wall stresses were compared between models that had intraluminal thrombus and the unmodified models. Stress reduction greater than 25% was considered significant. RESULTS: The maximum stress reduction of 51% occurred when thrombus with elastic modulus of 1.0 MPa filled the entire AAA cavity. Stresses were reduced by only 25% as modulus decreased to 0.2 MPa. Similarly, decreasing thrombus size by 70% resulted in stress reduction of only 28%. Large AAAs experienced greater stress reduction than small AAAs (48% vs 11%). CONCLUSION: Intraluminal thrombus can significantly reduce AAA wall stress.     

Anterior patch aortic aneurysm model for the study of endoluminal grafts

Endovascular graft repair for aortic aneurysms has led to concerns regarding the healing characteristics of the graft within a thrombus-lined aneurysm and the effect that collateral flow may have on the endoluminal prosthesis and the aneurysm. An anterior aortic patch aneurysm model that preserved collateral arteries was examined and modified to address these issues. In canines (n = 30) a Dacron knitted patch (n = 27) or a rectus fascia patch (n = 3) was sutured into a 3.5-cm anterior aorotomy. Dacron patch aneurysm diameter was an average of 21.8 +/- 2.2 mm (mean canine normal aortic diameter 9.06 +/- 0.79 mm). Canines underwent angiogram, computed tomography, and/or intravascular ultrasound from 1 to 11 weeks later, at which time an endoluminal prosthesis was deployed and followed 30 to 60 days until harvest. Aneurysms accumulated minimal thrombus through the initial 11 weeks. Significant stenosis (mean 21.2% +/- 19%) occurred at aneurysm necks in association with a patch imbrication suture technique (n = 11). Following modification (n = 16), this decreased to a mean of 3.6 +/- 9.7%. Collateral lumbar artery patency was 95% at the time of imaging prior to graft placement. Following successful graft implantation, 16 of 18 aneurysms were filled with thrombus and in most cases the collateral circulation occluded. One of three fascial patch aneurysms ruptured 21 days after creation. This model more accurately depicts abdominal aortic aneurysms with the inherent thrombus and collateral flow that is important when studying aspects of endovascular aortic graft repair.     

Postprocessing techniques for gadolinium-enhanced three-dimensional MR angiography

Contrast material-enhanced three-dimensional (3D) magnetic resonance (MR) angiography is rapidly gaining acceptance as a versatile noninvasive alternative to conventional angiography. The technique has proved useful in the visualization and assessment of complex pathologic entities in the thoracic and abdominal aorta, renal arteries, pelvic arterial system, and pulmonary arteries. Several postprocessing techniques are available for reformation of the imaging data, including maximum intensity projection (MIP), surface rendering, and virtual intraluminal endoscopy (VIE). MIP and subvolume MIP reconstructions can be produced quickly and are useful for demonstration and archiving purposes. Because of its unique ability to display vessels without overlap, surface rendering is especially useful in depicting diseases that influence either the outer shape of the vessels or their topographic arrangement. VIE allows assessment of the inside of the vascular wall and is helpful in detecting wall-bound thrombus and evaluating the degree of stenosis. Most clinically relevant questions (eg, presence of pulmonary embolism, aortic aneurysm, renal artery stenosis) can be fully answered if analysis is based on MIP and thin multiplanar reformations of contrast-enhanced 3D MR angiograms. In some cases, the use of additional postprocessing techniques enhances diagnostic confidence.     

Cellular localization of kallistatin and tissue kallikrein in human pancreas and salivary glands

We studied the effects of the new antioxidant drug U-83836E during splanchnic artery occlusion (SAO) shock in the rat. Serum tumor necrosis factor (TNF-alpha), white blood cell (WBC) count, mean arterial blood pressure (MAP), survival rate and the responsiveness to acetylcholine of aortic rings were investigated. SAO shock produced a marked increase in serum TNF-alpha (241.4 +/- 18.2 U/ml vs Not Detectable in basal), reduced MAP (51.4 +/- 4 mmHg vs 85.1 +/- 5 mmHg), survival time (80 +/- 10 min vs > 240 min), WBC count (2.8 +/- 0.4 x 10(3)/mm3 cells vs 11.7 +/- 0.9 x 10(3)/mm3 cells) and blunted the responsiveness to ACh of aortic rings (60 +/- 3% tension vs 23 +/- 4% tension). The analogue of vitamin E, U-84836E, administered at onset of reperfusion, lowered serum TNF-alpha (38.4 +/- 6.5 U/ml; p < 0.001), improved MAP (67.5 +/- 3.8 mmHg; p < 0.001), WBC count (8.9 +/- 0.6 x 10(3)/mm3; p < 0.001), and survival time (235 +/- 15 min; p < 0.001), and restored the responsiveness to ACh of aortic rings (32 +/- 3.7% tension; p < 0.001). These preliminary data suggest that this new compound could be a promising drug in shock therapy.     

Comparative efficacy of chloroquine plus chlorpheniramine and halofantrine in acute uncomplicated falciparum malaria in Nigerian children

A 47-year-old woman on long-term hemodialysis due to a chronic isolated abdominal aortic dissection was admitted to our department with severe abdominal pain. She had not suffered any hematemesis or melena. An emergency laparotomy revealed an abdominal aortic aneurysm with a diameter of 60mm, densely adhered to the ileum. An aortoenteric fistula manifesting as intramural rupture into the ileum was found after infrarenal abdominal aortic and bilateral common iliac cross-clamping. The fistula on the ileac side was nontransmural, but that on the aortic side communicated with the pseudolumen of the abdominal aorta, and contained mural thrombus. The infrarenal abdominal aorta and bilateral common iliac arteries were replaced with a collagen-sealed woven Dacron bifurcated graft. Histological examination of the ileum in this portion showed intramural bleeding and xanthomatous granulation with foam cell infiltration in the thickened subserosa. While it is difficult to diagnose nonpenetrating aortoenteric fistula preoperatively, such a fistula must be considered in a patient with severe abdominal pain, for whom previous abdominal aortic surgery has been performed or when an abdominal aneurysm is observed. To our knowledge, no other case of an aortoenteric fistula presenting as an intramural rupture into the ileum in an isolated abdominal aortic dissection has ever been reported.     

Stents in aortic coarctation. Immediate results

From September 1996 to March 1997 we implanted stents Palmaz (P-308 Johnson & Johnson) in six patients with aortic coarctation. Age ranged from 13 to 30 years (mean = 20), 3 female and 3 male. We implanted the stent without predilation. Balloon diameter was 12 mm in two cases and 15 mm in four cases for complete expansion we used 14 to 20 mm balloon diameter in five instances and in one case we used a dual balloon 15 + 15 mm. The gradient pre-stent ranged from 30 to 65 mmHg (mean = 44) and decreased to 0 mmHg in five cases and in one patient the residual gradient was 4 mmHg. Systolic aortic pressure pre-stent was 135 mmHg and decreased to 117 mmHg. There were no significant complications. In conclusion, we have demonstrated the feasibility of balloon-expandable stent implantation as a method of alleviation the obstruction in coarctation of the aorta in this group of patients. It is an excellent alternative to surgical treatment and it is better than balloon angioplasty that results in marked improvement in the angiographic appearance of the thoracic aorta. It eliminates the gradient, has minimum morbidity and no mortality, no aneurysm formation. Late restenosis and possible aneurysm formation remains an unlikely complication in view of the ample luminal diameter and the high velocity of flow.     

Conservative therapeutic approaches in terminal coronary heart disease. Chronic intermittent urokinase therapy

The plasma concentration of lipoprotein(a) [Lp(a)] is highly correlated with the incidence of cardiovascular and peripheral vascular disease. A positive physiological role for Lp(a) has not yet been clearly identified, although elevated plasma levels in pregnant women, long-distance runners, subjects given growth hormone, patients after cardiovascular surgery, and patients with cancer, diabetes, or renal disease suggest its involvement in tissue synthesis and repair. The hypothesis that Lp(a) is involved in repair/reinforcement of the aorta was tested in 38 patients undergoing surgery for aortic aneurysm. In 29 patients 1 day before surgery, the mean plasma Lp(a) protein level was 10.7 mg/dl. At about 1, 2, and 8 weeks after surgery, the level was 14.1, 15.1, and 15.2 mg/dl, respectively. These levels are significantly higher than those of a comparable group of normal subjects (6.4 mg/dl; n = 274). Specimens of resected aortic aneurysm showed extensive medial degeneration, discontinuous elastic fibers, and deposition of mucopolysaccharides; these specimens were treated with a detergent-containing buffer to extract entrapped lipoproteins. The mean Lp(a) protein level in aortic wall extracts was 14.6 ng/mg tissue; these individual values were significantly associated with plasma Lp(a) levels before surgery (r2 = 0.31, p = 0.0003). The mean Lp(a) protein level in aortic thrombus extracts was substantially higher at 69.6 ng/mg tissue; these individual levels also were significantly associated with plasma Lp(a) concentrations before surgery (r2 = 0.68, p < 0.0001). The observations that: (i) plasma Lp(a) protein is about 1.7-fold higher in patients with aortic aneurysms than in normal subjects; and (ii) that Lp(a) protein in the aneurysmic thrombus is about 4.8-fold higher than in the aortic wall suggest that this lipoprotein plays a significant and direct role in thrombus formation and in reinforcement of the aneurysmic aortic wall.     

Long term relative survival after surgery for abdominal aortic aneurysm in western Australia: population based study

OBJECTIVE: To determine the long term relative survival of all patients who had surgery for abdominal aortic aneurysm in Western Australia during 1985-94. DESIGN: Population based study. SETTING: Western Australia. SUBJECTS: All patients who had had surgery for abdominal aortic aneurysm in Western Australia during 1985-94. MAIN OUTCOME MEASURES: Morbidity and mortality data of patients admitted and surgically treated for abdominal aortic aneurysm in Western Australia during 1985-94. Elective, ruptured, and acute non-ruptured cases were analysed separately. Independent analyses for sex and patients aged 80 years or more were also undertaken. Postoperative (>30 days) relative survival was assessed against age and sex matched controls. RESULTS: Overall, 1475 (1257 men, 218 women) cases were identified. The crude five year survival after elective surgery, including deaths within 30 days of surgery, was 79% for both men and women. When compared with a matched population the five year relative survival after elective surgery was 94.9% (95% confidence interval 89.9% to 99.9%) for men but only 88.0% (76.3% to 99.7%) for women. The five year relative survival of those aged 80 years and over was good: 116.6% (89.1% to 144.0%) compared with 92.4% (87.7% to 97.0%) for those under 80 years of age (men and women combined). Cardiovascular disease caused 57.8% of the 341 deaths after 30 days. CONCLUSION: In a condition such as abdominal aortic aneurysm, which occurs in elderly patients, relative survival is more clinically meaningful than crude survival. The five year relative survival in cases of elective and ruptured abdominal aortic aneurysm was better in men than in women. This is probably because of greater comorbidity in women with abdominal aortic aneurysm and this deserves more attention in the future. The long term survival outcome in octogenarians supports surgery in selected cases.     

Immediate postgadolinium spoiled gradient-echo MRI for evaluating the abdominal aorta in the setting of abdominal MR examination

To assess the reproducibility and image quality of immediate postgadolinium chelate spoiled gradient-echo MRI in demonstrating disease of the abdominal aorta. All patients (27 patients: 21 men, 6 women) with substantial disease of the abdominal aorta, who underwent abdominal MR examinations at 1.5 T between 1991 and 1995, were entered in the study. Patients were referred for evaluation of suspected aortic disease (14 patients) or other abdominal diseases (13 patients). Three experienced investigators manually measured luminal and external aortic wall diameters and rated image quality, definition of inner and outer walls, extent of disease, and presence of other abdominal abnormalities, in an independent fashion. A cardiovascular surgeon then rated all studies to determine whether clinical management could be based on the MR findings alone. There was 98 to 99% agreement in measurements of luminal and external wall diameter between the three investigators. Overall image quality was rated as good in 77.8 to 88.9% of patients. A total of 31 additional nonaortic abdominal abnormalities were detected by all observers. The cardiovascular surgeon rated 25 of 27 studies as adequate to determine clinical management based on MR findings alone. Immediate postgadolinium spoiled gradient-echo MRI is a reproducible technique for the demonstration of abdominal aortic disease and possesses good image quality. Advantages of this technique include simultaneous evaluation of other nonvascular diseases of the abdomen, short examination time, and easy implementation as part of routine abdominal MRI scanning protocol.     

Ruptured abdominal aortic aneurysm presenting with acute urinary retention

Ruptured abdominal aortic aneurysm classically presents with abdominal pain radiating to the back, a pulsatile abdominal mass and circulatory collapse. However, other symptoms may be the only presenting complaint. We report the case of a patient who presented with a history of acute retention of urine relieved by catheterisation, but who then developed clinical features more typical of abdominal aortic aneurysm rupture.     

Fate of the excluded abdominal aortic aneurysm sac: long-term follow-up of 831 patients

PURPOSE: Nonresective treatment of the infrarenal abdominal aortic aneurysm by proximal and distal ligation of the aneurysm sac (exclusion) combined with aortic bypass has been previously reported. A 10-year experience with 831 patients undergoing this procedure was reviewed. METHODS: From 1984 to 1994, 831 (761 elective, 70 urgent) of 1103 patients being treated for abdominal aortic aneurysm underwent repair with the retroperitoneal exclusion technique. Perioperative morbidity and mortality, estimated blood loss, transfusion requirements, natural history of the excluded aneurysm sac, and long-term survival were all assessed. RESULTS: The operative mortality rate for patients undergoing exclusion and bypass was 3.4%. The incidence of nonfatal perioperative complications was 5.2%. Colon ischemia requiring resection occurred in 2 (0.2%) of the 831 patients. Estimated blood loss was 638 +/- 557 cc (50 to 330 cc). On follow-up 17 (2%) patients were found to have patent aneurysm sacs as detected by duplex examination. Fourteen patients required surgical intervention. No cases of graft infection or aortoenteric fistula have been noted. CONCLUSION: Retroperitoneal exclusion and bypass is a viable alternative to traditional open endoaneurysmorraphy in surgery for abdominal aortic aneurysm. Most excluded aneurysm sacs have thrombosis without any long- or short-term complications; however, in a small number of patients delayed rupture of patent aneurysm occurs, thus emphasizing the need for diligent follow-up and appropriate intervention.     

Continuous spinal analgesia. Comparison between patient-controlled and bolus administration of plain bupivacaine for postoperative pain relief

The purpose of this study was to examine the changing trends in surgical management of patients with abdominal aortic aneurysms at a tertiary care teaching hospital over the past 40 years, by analysis of demographic data, perioperative variables and outcomes on all patients having abdominal aortic aneurysm surgery between 1955 and 1993. Some 1604 abdominal aortic aneurysms were assessed. The annual rate of abdominal aortic aneurysm surgery increased from 17.6 to 67.8 cases per year. The non-ruptured to ruptured abdominal aortic aneurysm ratio increased from 2.4:1 in the first decade to 3.4:1 in the last 5 years. In non-ruptured abdominal aortic aneurysm repairs, the following variables changed over the four decades: patients age over 80 years increased (2.4% to 8.0%; P<0.04), concomitant lower-limb occlusive disease increased (12.2% to 23.7%; P<0.02), prevalence of smaller aneurysms (4-6 cm) increased (16.0% to 54.2%; P<0.0001); intraoperative hypotension decreased (9.0% to 0.7%; P<0.0001), postoperative hemorrhage decreased (8.2% to 0.0%, P<0.0001), postoperative leg ischemia decreased (5.7% to 1.1%; P<0.02) and postoperative amputation rate decreased (3.2% to 0.0%; P<0.03). There was a significant decrease in perioperative mortality (17.0% to 3.4%; P<0.0001). For ruptured aneurysms, early operation (within 1 h of admission) increased from 8.7% to 55.8% (P<0.0001), prevalence of intraoperative hypotension decreased (50.0% to 23.5%; P<0.001), and major venous injury decreased (18.0% to 5.2%; P<0.05). Mortality, however, did not decrease significantly (54.2% to 44.2%; P=0.32). In conclusion, there was a significant decrease in mortality and morbidity associated with non-ruptured abdominal aortic aneurysm repair over the four decades studied. In addition, older patients with smaller aneurysms and more co-morbid conditions were operated on during this period. Mortality for patients operated on for ruptured abdominal aortic aneurysm repair has not changed significantly.     

Preparation for upper gastrointestinal endoscopy: opportunity or inconvenience?

A 59-year-old man, who manifested lower back pain, was admitted with sepsis and disseminated intravascular coagulation (DIC). A computed tomographic scan showed a slight thickening of the abdominal aortic wall. A blood examination revealed pancytopenia. Myelodysplastic syndrome was diagnosed after bone marrow aspiration and a chromosome analysis. Sepsis due to a Staphylococcus aureus infection and DIC subsided after medical treatment; however, an aortobifemoral bypass was performed upon the detection of a localized rupture of a mycotic abdominal aortic aneurysm 1 month later. The patient is still alive 2 years after operation despite the presence of a hematological disorder.     

A new T-tube applier in laparoscopic surgery

The level of blood lipids and apolipoproteins in subjects being screened for abdominal aortic aneurysms have been investigated. As part of an ultrasound screening programme in a population of 65- to 75-year-olds, blood samples were collected from 1460 of 1504 subjects with a normal aorta (97.1%) and 69 of 70 patients with an abdominal aortic aneurysm > 29 mm (99%). Samples were also taken from 22 of 27 patients (81%) with an ectatic aorta (26-29 mm). Total cholesterol, HDL-cholesterol, LDL-cholesterol, Apo-AI and Apo-B levels were significantly higher in women than in men (P < 0.01). Levels of HDL-cholesterol and Apo-AI were significantly lower in patients with an abdominal aortic aneurysm than in normal subjects (P < 0.001). The mean(s.d.) body mass index was 25.1(3.9) in women and 25.5(3.2) in men with aneurysms and not significantly greater than that of normal subjects (25.2(3.61) and 25.2(3.38) respectively).     

Experimental creation of fusiform carotid artery aneurysms using vein grafts in rats

OBJECTIVE: We developed an in vivo model of growing fusiform aneurysms, using vein grafts to the rat carotid artery. This aneurysm model might demonstrate the pathological features of the development and growth of aneurysms to become giant aneurysms. METHODS: Placement of an interposed femoral vein graft to restore carotid artery flow was performed in Wistar rats. On Day 21, 75% of the grafts (mean diameter, 1.6 mm) were found to be dilated to resemble fusiform aneurysms (mean diameter, 5.82 mm), and 53% of these were giant. Quantitative analysis of the histological findings was performed using image-analyzing software. RESULTS: Histological findings were similar to those for human intracranial giant aneurysms. The average length of the initial grafts in the aneurysm group was 9.1+/-1.9 mm, and grafts were significantly longer and more tortuous than in the normal graft group (6.4+/-0.8 mm) (P = 0.01). Cross-sectional areas of the aneurysms (mean, 18.9 mm2) were significantly correlated with the following: 1) the area of intra-aneurysmal thrombosis (mean, 11.1 mm2) (P < 0.0001); 2) the number of intrathrombotic vascular channels (P = 0.005); and 3) the area of dissection, with hemorrhage, between the thrombus and the wall of the aneurysm (mean, 0.72 mm2) (P = 0.0013). Scanning electron microscopic examination showed evidence of endothelial damage associated with growth of the aneurysms. CONCLUSION: Recurrent hemorrhaging from intrathrombotic vascular channels caused dissection between the thrombus and the aneurysm wall, which led to growth of the experimental aneurysms to giant aneurysms. With this model, we demonstrated the growth mechanism of giant fusiform aneurysms.     

Occluded peripheral arteries and bypass grafts: lytic stagnation as an end point for pulse-spray pharmacomechanical thrombolysis

Angiographic demonstration of luminal narrowing during pulse-spray pharmacomechanical thrombolysis (PSPMT) may reflect residual lysable clot, organized thrombus, platelet-rich clot, atherosclerosis, neointimal hyperplasia, or functional narrowing. The authors evaluated the efficacy and safety of lytic stagnation (initial rapid lysis followed by insubstantial further lysis with additional treatment) as an end point for PSPMT. Lytic stagnation was evaluated with serial angiography in 16 arterial and five bypass graft occlusions. Substantial lysis occurred after administration of mean doses of 512,000 units +/- 182,000 of urokinase or 5.3 mg +/- 2.0 of tissue-type plasminogen activator. Additional treatment with either of those agents produced minimal or no further change in the appearance of residual disease. Recanalization was successful in all patients after angioplasty. Distal emboli were noted in four cases, in three of which angioplasty of large intraluminal filling defects had been performed. The authors conclude that lytic stagnation is a reliable and safe end point for PSPMT in the absence of large intraluminal filling defects.     

Chronic rupture of abdominal aortic aneurysms

INTRODUCTION: Rupture of abdominal aortic aneurysms (RAAA) can take place in one of the 4 following ways: 1. "Open" rupture in the free peritoneal cavity; 2. "Closed" rupture with formation of retroperitoneal haematoma; 3. Rupture into surrounding cavity structures, such as veins and bowels; 4. In rare cases rupture is effectively "sealed of" by the surrounding tissue reaction, and retroperitoneal haematoma is "chronically" contained [1]. The terms "sealed" [2], "spontaneously healed" [3], "leakig" [4] RAAA, were also used in the previous papers connected to this situation. The "sealed" rupture was first described by Szilagyi and associates in 1961 [2]. In their case the rupture was small and haemorrhage was effectively encircled by the tissue surrounding the aortic wall. The slow rate of blood loss contributed to the patient's haemodinamically stable condition. Christenson et al. reported a case of "spontaneously healed" RAAA [3]. Rosenthal and associates described 2 patients who had aortic aneuryms that ruptured several months before repair and contributed to the term "leaking AAA" [4], while Jones et al. introduced the term "chronic contained rupture" [1]. The aim of this paper is the presentation of 5 such patients. CASE REPORT: Between December 1, 1988 and May 30, 1997 411 patients with abdominal aortic aneurysms (AAA) have been operated at our institute. Of this number 137 (33%) had RAAA, while 5 patients (12%) had a contained RAAA (CRAAA). CRAAA were found in 3 male and two female patients, average age 62 years. All of them had a previously proved AAA and initial symptoms lasted for days or months before the admission. In all patients haematocrit, pulse rate and arterial tension during the admission, were normal. All typical signs of RAAA were absent in these patients. Patient 1. A 56-year-old man, smoker, with previous history of arterial hypertension had an isolated episode of abdominal pain and collapse 30 days before the admission. Physical examination revealed a pulsatile abdominal mass. Doppler ultrasonography identified an infrarenal AAA, with right lobular extraaneurysmal mass which displaced the inferior vena cava (ICV). Angiographically (Figure 1a) an unusual saccular intrarenal AAA was detected, while simultaneous cavography (Figure 1b) confirmed the-dislocated inferior vena cava to the right. The intraoperative finding showed infrarenal CRAAA with organized retroperitoneal haematoma between AAA, ICV and duodenum. After aortic cross clamping and aneurysmal opening, the rupture at the right posterior aneurysmal wall was discovered. The partial aneurysmactomy and aortobilliar bypass procedure with bifurcated knitted Dacron graft (16 x 8 mm), were performed. The patient recovered very well. After a 4-year follow-up period the graft is still patent. Patient 2. A 72-year-old woman with low back pain, fever and disuric problems was urgently admitted to the Institute of Urology and Nephrology. The standard urological examination (X-ray, intravenous pyelography, retrograde urography, kidney Duplex ultrasonography) excluded urological diseases. However, intrarenal AAA an a giant aneurysm of the right common iliac artery, were found. The proximal dilatation of the right excretory urinary system was also found by retrograde urography. The patient was transported to our Institute 20 days after the initial symptoms. Translumbar aortography (Figure 3) showed the right common iliac artery aneurysm and gave the false negative picture of normal abdominal aorta because of parietal thrombosis of AAA. The intraoperative finding showed chronic rupture of the posterior wall of the right common artery aneurysm. The retroperitoneal haematoma compressed the right ureter. Both aneurysm have been resected and replaced by bifurcated Dacron graft (16 x 8 mm). The patient recovered successfully. After a 2-year period of follow-up the graft is still patent. Patient 3. (ABSTRACT TRUNCATED)     

Infrarenal aortic dimensions in siblings of patients with infrarenal abdominal aortic aneurysm or aortoiliac occlusive disease

OBJECTIVE: To compare the dimensions of the infrarenal aorta and the prevalence of undiagnosed infrarenal abdominal aortic aneurysms in the siblings of patients operated on for either infrarenal abdominal aortic aneurysm or aortoiliac occlusive disease. DESIGN: Prospective screening study. SETTING: University hospital, Finland. SUBJECTS: 220 siblings of patients operated for either abdominal aortic aneurysm or aortoiliac occlusive disease. INTERVENTIONS: Abdominal aortic ultrasound. MAIN OUTCOME MEASURES: Anteroposterior and transversal diameters of infrarenal and suprarenal aorta. RESULTS: There was a group of 5 siblings (4 men and 1 woman, aged 59 years or more) among the aneurysm patients who had a disposition to infrarenal aneurysm formation defined as a dilatation of 30 mm or more. This contrasted with none among the siblings of the patients with aortoiliac occlusive disease (p = 0.07, 95% confidence interval 0.49 to 165.3). The two factors affecting the diameter of the infrarenal aorta were age and sex. The aortic dimensions tended to be bigger in the siblings of the aneurysm patients but the differences were not significant. The ratio of infrarenal to suprarenal diameter was bigger in the siblings of the aneurysm patients also after excluding the cases with detected dilatations (p = 0.05) and in the multivariate analysis the only factor explaining this difference was the type of the disease of the proband. CONCLUSIONS: The screening of male siblings (over 55 years old) of patients with infrarenal abdominal aortic aneurysms might be justified.     

The role of gammadelta T cells in induction of bacterial antigen-specific protective CD8+ cytotoxic T cells in immune response against the intracellular bacteria Listeria monocytogenes

PURPOSE: To study the relation between abdominal aortic aneurysms and chronical obstructive pulmonary disease (COPD), in particular the suggested common elastin degradation caused by elastase and smoking. METHODS: A cross-sectional population study and a prospective cohort study of small abdominal aortic aneurysms was performed in a community setting. All previous diagnoses recorded in a hospital computer database were received for 4404 men 65 to 73 years of age who had been invited to a population screening for abdominal aortic aneurysm. One hundred forty-one men had AAA (4.2%). They were asked to participate in an interview, a clinical examination, and collection of blood sample. Men with an abdominal aortic aneurysm 3 to 5 cm in diameter were offered annual ultrasound scans to check for expansion. RESULTS: Among patients with COPD 7.7% had abdominal aortic aneurysms (crude odds ratio=2.05). The adjusted odds ratio, however, was only 1.59 after adjustment for coexisting diseases associated with abdominal aortic aneurysm (P=.13). The mean annual expansion was 2.74 mm per year among patients with COPD, 2.72 among patients without COPD, and 4.7 mm among patients who used oral steroids compared with 2.6 among patients who did not use steroids (P < .05). Concentration of serum elastin peptide and plasma elastase-alpha1-antitrypsin complexes correlated negatively with forced expiratory volume in the first second (FEV1) among patients with COPD. However, multivariate regression analysis showed that concentration of serum elastin peptide, therapy with beta-agonists, and FEV1 correlated positively with degree of expansion but that concentration of plasma elastase-alpha1-antitrypsin complexes and serum alpha1-antitrypsin did not influence expansion, suggesting that elastase plays an important role in the pathogenesis of COPD but not of abdominal aortic aneurysm. CONCLUSION: The high prevalence of abdominal aortic aneurysm among patients with COPD is more likely to be caused by medication and coexisting diseases rather than a common pathway of pathogenesis.     

Results of autopsy 7 months after successful endoluminal treatment of an infrarenal abdominal aortic aneurysm

PURPOSE: To report the results of a postmortem examination in a patient who died of unrelated causes 7 months following endoluminal treatment of an infrarenal abdominal aortic aneurysm (AAA). METHODS: As part of an FDA Phase I pilot study, a 73-year-old man underwent successful endoluminal exclusion of an infrarenal AAA using a 9-cm-long endograft (Endovascular Grafting System). Seven months later, he succumbed to complications of a spontaneous esophageal rupture. At autopsy, the aorta was dissected in situ by a vascular surgeon and pathologist before being explanted in order to examine the wound healing characteristics at the aorta-endograft interface. Particular attention was also directed to the hooks composing the attachment system at each end of the endograft. RESULTS: Macroscopic and microscopic examination revealed that the graft had completely excluded the aneurysm sac from the circulation and was incorporated into the aortic wall at the proximal neck and distal cuff. A smooth pannus of endothelial cells covered the proximal end of the endograft at the areas of contact with the aorta, while microscopic examination of the distal end of the graft revealed poorly formed, fibrinous pannus. The neointima deep to the endothelium consisted of a collagenous matrix containing myofibroblasts and histiocytes, providing evidence of healing between the endograft and aorta. Both renal arteries were clear of the proximal end of the endograft, but a previously unrecognized right lower pole renal artery with an extremely caudal origin was excluded from the aortic lumen. Each hook of the attachment system was seen protruding through the adventitia of the aorta. There was no evidence of trauma to the aortic wall or the surrounding tissues caused by these hooks. CONCLUSION: There appears to be evidence that an endoluminally placed aortic graft may be incorporated by the host aortic tissue.