Natural history of abdominal aortic aneurysm detected by screening

A group of 88 patients with abdominal aortic dilation found in four ultrasonographic screening studies was followed prospectively by repeated ultrasonography. The initial aortic diameter ranged between 18 and 70 mm. In 19 patients (22 per cent) the aortic diameter exceeded 39 mm. The mean (s.e.m.) annual expansion rate of dilatations < 40 mm in diameter was 0.8 (1.2) mm; among those > or = 40 mm it was 3.3 (1.2) mm. The expansion rate increased with increasing initial diameter. Thirty-eight patients died; the overall mortality rate in the group was high in comparison with an age- and sex-matched population. One patient died after elective aneurysm surgery but none died from a ruptured aneurysm. In conclusion, in about 80 per cent of dilatations found in screening studies the aortic diameter was < 40 mm, with a low risk of rupture. One annual rescanning of an aneurysm < 35 mm in diameter is sufficient; a high overall mortality rate must be expected.     

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.     

Diagnosis and treatment of abdominal aortic aneurysms

Abdominal aortic aneurysms occur in 5 to 7 percent of people over age 60 in the United States. An aneurysm is defined as a permanent localized dilatation of an artery, with an increase in diameter of greater than 1.5 times its normal diameter. Abdominal aortic aneurysms may be manifested by catastrophic rupture, signs of pressure on other viscera or an embolism originating in the aneurysmal wall, but most cases are asymptomatic. The diagnosis is often made by physical examination of the abdomen, which reveals a pulsatile mass left of the midline, between the xyphoid process and the umbilicus. The diagnosis may be confirmed by B-mode ultrasound. Ultrasound screening should be considered for individuals at risk for abdominal aortic aneurysms. This group includes individuals over age 60 who smoke, have hypertension or have vascular disease. Elective surgical intervention is indicated for most patients with abdominal aortic aneurysms greater than 5 cm in diameter to prevent rupture and death. Smaller abdominal aortic aneurysms should be monitored by regular ultrasound measurements. Screening and identification of abdominal aortic aneurysms by primary care physicians can have a significant impact on patient survival.     

A statistical analysis of the growth of small abdominal aortic aneurysms

Screening for abdominal aortic aneurysm has been offered to 13,000 patients. An overall compliance of 76% (range 51-99%) has been achieved. For those with an initial aortic diameter between 29 mm and 45 mm serial ultrasound scans are offered to monitor aortic change. Of the 302 cases followed up by repeated scans, 93 have had more than 5 scans (mean of 7 scans) over a mean time period of 32.1 months (range 15-63 months). The rate of change of all these aneurysms has been calculated using all data points and robust linear regression. It has been possible to postulate an algorithm for aortic growth. The influence of measurement precision and ultrasound quality assurance on the rescan interval is demonstrated and it is suggested that 2 years is a suitable rescan interval for aortas with diameter less than 40 mm.     

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.     

High-speed, three-dimensional kinematic analysis of the normal wrist

PURPOSE: To identify the predictive risk factors for rupture of thoracoabdominal aortic aneurysms (TAA). METHODS: Thirty-one patients with TAA who did not have the indications for surgical repair of the aneurysm were selected. Inclusion criteria were maximum diameter less than 60 mm, refusal of surgical treatment, and high surgical risk. The selected patients participated in a prospective follow-up study for a median period of 47 months and underwent at least two thoracoabdominal computed tomographic scans a year to measure transverse and anteroposterior diameters. Identification of the predictive factors associated with rupture was undertaken with multivariate analysis by means of Cox regression model. RESULTS: During the study period five patients underwent elective repair, six died of unrelated causes, nine had aneurysms that ruptured (all with diameters greater than 50 mm), and 11 reached the end of the study without rupture or surgical management. Initial anteroposterior diameter and annual growth rate of the anteroposterior diameter were the variables associated with rupture of the TAA according to the multivariate statistical analysis by means of Cox regression model. CONCLUSION: We recommend elective repair for a fit patient with asymptomatic TAA with an initial anteroposterior diameter of 50 mm only when there is an annual growth rate of at least 10 mm. Patients with similar diameters but with smaller annual growth rates should be treated conservatively and undergo thoracoabdominal computed tomography every 6 months. Patients with an initial anteroposterior diameter of 60 mm and an annual growth rate of 6 mm should undergo surgical treatment. These guidelines for elective repair of TAA are based on the results of a relatively small series and have to be carefully individualized for each patient.     

A prospective study to define the optimum rescreening interval for small abdominal aortic aneurysm

A prospective study of 99 patients with small abdominal aortic aneurysms was undertaken using serial ultrasound to assess the optimum screening interval. Fifty-three patients had aneurysms measuring 2.5-3.9 cm and 46 patients aneurysms of 4.0-4.9 cm. Aneurysms measuring 2.5-3.9 cm were screened annually and those > 4.0 cm every 6 months. There were eight deaths in the 2.5-3.9 cm group, none attributable to a ruptured aneurysm and five patients have had their aneurysm repaired. Nine patients died in the 4.0-4.9 cm group, one with a ruptured aneurysm measuring 5.6 cm at her previous screening visit and who was unfit for operation. No other patient had an aneurysm which ruptured between scans. There were seven elective repairs in this group. No patient died following elective operation in either group. The mean growth rate of aneurysms in the 2.5-3.9 cm group was 2.2 mm in the first year, 2.8 mm in the second and 1.8 mm in the third. Corresponding growth rates in the 4.0-4.9 cm group were 2.7 mm, 4.2 mm and 2.2 mm. This study supports a policy of annual screening for aneurysms measuring 2.5-3.9 cm and 6-monthly screening for those > or = 4.0 cm.     

Current status of the use of retroperitoneal approach for reconstructions of the aorta and its branches

OBJECTIVE: The objective of this article is to determine whether retroperitoneal approach for aortic surgery has certain physiologic, technical advantages. SUMMARY BACKGROUND DATA: The retroperitoneal approach for abdominal aortic reconstruction classically had been reserved for select patients with either high-risk comorbid disease or specific anatomic problems that preclude the transabdominal approach. With increasing appreciation of the physiologic, anatomic, and technical advantages of the extended posterolateral retroperitoneal approach, the authors have expanded its use for repair of all types of aortic visceral and renal artery disease as well as ruptured abdominal aortic aneurysm and infected aortic grafts. METHODS: From January 1981 to September 1995, 2340 retroperitoneal aortoiliac reconstructions were performed in 2243 patients. Aortic reconstructions accounted for 1756 cases: 1109 for elective abdominal aortic aneurysms, 210 for ruptured and symptomatic aortic aneurysms, 399 for occlusive disease, 18 for infected aortic grafts, and 20 for other indications. Iliofemoral disease was the indication for 584 procedures. As experience was gained, this approach also was used for 417 renal and 50 celiac and superior mesenteric artery reconstructions. RESULTS: The mean age was 67 years with 1590 men and 653 women. Overall mortality was 5.2% for all aortic cases: 2.4% for elective, 12.6% for symptomatic, and 29.0% for ruptured aortic aneurysms. Major complications occurred in 12.5% of the elective procedures and in 38.3% of emergency procedures. Over the past 5 years, the average length of hospital for uncomplicated elective abdominal aortic aneurysms was 6.1 days, intensive care unit stay was 0.7 day, and diet was resumed by postoperative day 1. Five-year graft patency was 99% for aneurysms and 95% for occlusive disease. CONCLUSIONS: The retroperitoneal approach offers certain physiologic advantages associated with minimal disturbance of gastrointestinal and respiratory function, thereby reducing the length of intensive care unit and hospital stay. In addition, its technical advantages and flexibility facilitates visceral and juxtarenal aortic reconstructions without the need for thoracotomy.     

Improved prognosis of thoracic aortic aneurysms: a population-based study

CONTEXT: Managing thoracic aortic aneurysms identified incidentally by increased use of computed tomography, echocardiography, and magnetic resonance imaging is problematic, especially in the elderly. OBJECTIVE: To ascertain whether the previously reported poor prognosis for individuals with thoracic aortic aneurysms has changed with better medical therapies and improved surgical techniques that can now be applied to aneurysm management. DESIGN: Population-based cohort study. SETTING AND PATIENTS: All 133 patients with the diagnosis of degenerative thoracic aortic aneurysms among Olmsted County, Minnesota, residents between 1980 and 1994 compared with a previously reported cohort of similar patients between 1951 and 1980. MAIN OUTCOME MEASURES: The primary clinical end points were incidence, cumulative rupture risk, rupture risk as a function of aneurysm size, and survival. RESULTS: In contrast to abdominal aortic aneurysms, for which men are affected predominately, 51% of thoracic aortic aneurysms were identified in women who were considerably older at recognition than men (mean age, 75.9 vs 62.8 years, respectively; P= .01). The overall incidence rate of 10.4 per 100000 person-years (95% confidence interval [CI], 8.6-12.2) between 1980 and 1994 was more than 3-fold higher than the rate from 1951 to 1980. The cumulative risk of rupture was 20% after 5 years. Seventy-nine percent of ruptures occurred in women (P= .01). The 5-year risk of rupture as a function of aneurysm size at recognition was 0% for aneurysms less than 4 cm in diameter, 16% (95% CI, 4%-28%) for those 4 to 5.9 cm, and 31% (95% CI, 5%-56%) for aneurysms 6 cm or more. Overall 5-year survival improved to 56% (95% CI, 48%-66%) between 1980 and 1994 compared with only 19% between 1951 and 1980 (P<.01). CONCLUSIONS: In this population, elderly women represent an increasing portion of all patients with clinically recognized thoracic aortic aneurysms and constitute the majority of patients whose aneurysm eventually ruptures. Overall survival for thoracic aortic aneurysms has improved significantly in the past 15 years.     

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.     

Endoleaks after endovascular graft treatment of aortic aneurysms: classification, risk factors, and outcome

PURPOSE: Incomplete endovascular graft exclusion of an abdominal aortic aneurysm results in an endoleak. To better understand the pathogenesis, significance, and fate of endoleaks, we analyzed our experience with endovascular aneurysm repair. METHODS: Between November 1992 and May 1997, 47 aneurysms were treated. In a phase I study, patients received either an endovascular aortoaortic graft (11) or an aortoiliac, femorofemoral graft (8). In phase II, procedures and grafts were modified to include aortofemoral, femorofemoral grafts (28) that were inserted with juxtarenal proximal stents, sutured endovascular distal anastomoses within the femoral artery, and hypogastric artery coil embolization. Endoleaks were detected by arteriogram, computed tomographic scan, or duplex ultrasound. Classification systems to describe anatomic, chronologic, and physiologic endoleak features were developed, and aortic characteristics were correlated with endoleak incidence. RESULTS: Endoleaks were discovered in 11 phase I patients (58%) and only six phase II patients (21%; p < 0.05). Aneurysm neck lengths 2 cm or less increased the incidence of endoleaks (p < 0.05). Although not significant, aneurysms with patent side branches or severe neck calcification had a higher rate of endoleaks than those without these features (47% vs 29% and 57% vs 33%, respectively), and patients with iliac artery occlusive disease had a lower rate of endoleaks than those without occlusive disease (18% vs 42%). Endoleak classifications revealed that most endoleaks were immediate, without outflow, and persistent (71% each), proximal (59%), and had aortic inflow (88%). One patient with a persistent endoleak had aneurysm rupture and died. CONCLUSIONS: Endoleaks complicate a significant number of endovascular abdominal aortic aneurysm repairs and may permit aneurysm growth and rupture. The type of graft used, the technique of graft insertion, and aortic anatomic features all affect the rate of endoleaks. Anatomic, chronologic, and physiologic classifications can facilitate endoleak reporting and improve understanding of their pathogenesis, significance, and fate.     

Genetic therapies for xenotransplantation

PURPOSE: To determine the optimal postoperative imaging modality for the follow-up of patients with endoluminal aortic stent grafts. MATERIAL AND METHODS: From August 1994 to November 1997, 214 patients (194 male and 20 female) with abdominal and thoracic aortic aneurysms were treated with endovascular stent grafts. 137 patients (129 male, 8 female) with 89 tube grafts and 48 bifurcated grafts (45 EVT, 88 Stentor/Vanguard, 3 Chuter, 1 Talent) were evaluated with contrast-enhanced spiral-CT, duplex ultrasound, and DSA at a mean follow-up of 11.1 months. RESULTS: We found 12 persistent primary endoleaks (8.8%), 17 secondary endoleaks (12.4%), 8 limb occlusions (5.8%), 28 endoluminal thrombi lining the stent graft (20.4%), and 26 suture breakages of the stent frame (19%). In 9 patients (6.6%) the proximal end of the stent partially covered the renal arteries. In 3 patients (2.2%) a partial renal infarction was seen. Spiral-CT was able to demonstrate all the above changes except for 3 sidebranch endoleaks that were documented by duplex ultrasound only and 8 suture breaks seen on abdominal plain films only. The median aneurysm diameter decreased from 48 mm pre-operatively to 46 mm at 24 months post-operatively in patients with endoleaks and from 44 mm to 36 mm in patients without endoleak. For several patients the decreasing aneurysm diameter did not reliably correlate with complete exclusion of the aneurysm. CONCLUSION: For follow-up of endoluminal aortic stent grafts contrast-enhanced spiral-CT is superior to duplex ultrasound. DSA is necessary only for patients with complications requiring a secondary intervention.     

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)     

Morphometric features of ruptured congenital sinus of Valsalva aneurysm: implication for surgical treatment

Five hearts with ruptured congenital sinus of Valsalva aneurysm were studied. In 3 hearts of Caucasian patients, the sinus of Valsalva aneurysms were located in the immediate vicinity of the commissure between the noncoronary and right aortic cusps with rupture from the noncoronary sinus to the right atrium (n = 2) and from the right sinus to the right ventricle (n = 1). In 2 hearts of indigenous North Americans, the defects were sited in the immediate vicinity of the commissure between right and left aortic cusps with rupture into the right ventricle; both patients had an associated conal septal hypoplasia ventricular septal defect and aortic insufficiency. The diameters of the rupture holes at the base of the sinus of Valsalva aneurysms in the five hearts ranged from 0.4 to 1.1 cm (mean 0.7 cm). Histologic examination of longitudinal sections through the ruptured sinus of Valsalva showed 0.8 to 1.7 cm (mean 1.1 cm) wide areas in which there was lack of continuity between the aortic media and the aortic annulus. Conclusions. This study shows that the site of congenital weakness in sinus of Valsalva aneurysm in indigenous North American patients may be similar to that in Oriental patients, whereas the site tends to be different in Occidental patients. It also emphasizes the importance of patch closure rather than suture closure of ruptured sinus of Valsalva aneurysms.     

Surgical treatment of thoracoabdominal aortic aneurysms]

Between February, 1981, and April, 1989, 20 patients underwent surgical treatment of thoracoabdominal aortic aneurysms. Most of the patients were operated under temporary external bypass. For Group I and III aneurysms without reconstruction of renal arteries, a modified Crawford's graft inclusion technique was employed to shorten abdominal visceral ischemic time. This modification consists of (1) using adjuncts to perfuse the distal aorta during aortic clamp, (2) starting the first anasistomosis from the distal end of the graft, and (3) shifting the distal aortic clamp on the graft after completing the anastomosis in order to restore abdominal visceral circulation as soon as possible. For Group III and IV aneurysms with reconstruction of renal arteries as well as celiac and superior mesenteric arteries, a modified DeBakey's procedure was employed. This modification consists of (1) using the spiral opening method, (2) doing end-to-end anastomosis at the proximal aortic site, and (3) maintaining the circulation of abdominal organs and spinal cord by using adjuncts during the anastomosis of the proximal end. There were one operative death and two hospital deaths. Paraplegia developed in two cases, one of which was a ruptured case. Renal dysfunction was not found in any case. The survivors were followed from 5 to 103 months, and there was no late death. The results suggest that our modified procedures for thoracoabdominal aortic aneurysms are useful and reliable ones.     

The fate of the infrarenal aortic neck after open aneurysm surgery

PURPOSE: The long-term success of the endovascular repair of abdominal aortic aneurysms is dependent on the secure fixation of the stent graft at the proximal and distal attachment sites. A progressive dilatation of the infrarenal neck may jeopardize this success. The data regarding this issue are scarce. However, the long-term fate of the infrarenal neck can be studied in patients who have undergone open aneurysm surgery. This was the purpose of the present investigation. METHODS: Between January 1989 and December 1993, 64 patients underwent open repair of infrarenal abdominal aortic aneurysms. Of the 36 patients who were eligible for the study, 19 had preoperative computed tomography scans that were available. The 19 patients also underwent a new computed tomography scanning at a mean of 71 +/- 12 months after surgery. RESULTS: The mean preoperative aortic diameter was 25.4 +/- 3.7 mm at the infrarenal neck, 24.8 +/- 3.4 mm at the level of the renal arteries, and 26.7 +/- 3.0 mm at the level of the superior mesenteric artery (SMA). The mean aortic diameter increased at all of the 3 levels: +2.8 +/- 3.1 mm (P =.0014) at the infrarenal neck, +2.8 +/- 3.0 mm (P =.0013) at the level of the renal arteries, and +1.3 +/- 3.0 mm (P = .080) at the level of the SMA. The annual growth rate was 0.48 mm/y (P = .0023) at the infrarenal neck, 0.46 mm/y (P =.0010) at the level of the renal arteries, and 0.21 mm/y (P = .5811) at the level of the SMA. No correlation was found between the preoperative infrarenal neck diameter (r = .295, P = .2194), the preoperative aortic diameter at the level of the renal arteries (r = .302, P = .2088), and the preoperative aortic diameter at the level of the SMA (r = .314, P =. 2043) and the corresponding growth rates. The patients were stratified into 2 groups one with a small annual growth rate at the infrarenal neck (n = 11; 0.3 mm/y) and no differences in the preoperative infrarenal neck diameter or the clinical characteristics were found between the groups. CONCLUSION: This investigation shows an aortic dilatation of the infrarenal neck and of the aorta at the level of the renal arteries of approximately 0.5 mm annually after open aneurysm surgery. This dilatation raises concern regarding the long-term success after endovascular repair. The data also indicate that 2 populations might exist with regard to the annual growth rate of the infrarenal neck one with low growth rate and one with higher growth rate. This might be of interest for the future selection of patients for endovascular repair.     

Anatomical suitability of abdominal aortic aneurysms for endovascular repair

BACKGROUND: Aortic aneurysm anatomy is crucial when considering patients for endovascular repair. The aim of this study was to determine the proportion of patients with aortic aneurysm suitable for endovascular repair with three different graft-stent systems. METHODS: Spiral computed tomographic angiography was used to assess the anatomy of 154 abdominal aortic aneurysms. Measurements were made of aneurysm neck length and diameter, renal artery to aortic bifurcation length, common iliac artery diameter and length, and external iliac artery diameter. Aneurysms were assessed for anatomical suitability for currently available aortoaortic, aortobi-iliac and aortouni-iliac devices. RESULTS: Six patients (4 per cent) had a distal aortic neck suitable for implantation of a straight aortic graft. Fifteen patients (10 per cent) had arterial anatomy suitable for implantation of a bifurcated graft and 85 (55 per cent) patients were suitable for endovascular repair with an aortouni-iliac graft. The primary reasons for unsuitability were: proximal neck length less than 1.5 cm (44 patients), proximal neck diameter greater than 3.0 cm (12), and angulation of the proximal neck (three). A further ten patients were considered unsuitable for an aortouni-iliac graft because of bilateral common iliac artery aneurysms (four), tortuous iliac arteries (four) and narrow external iliac arteries (two). CONCLUSION: The aortouni-iliac device has the widest applicability of the currently available endovascular systems but open repair remains the only option for a large proportion of patients.     

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).     

Topical anesthesia: Proxymetacaine versus Amethocaine for clear corneal phacoemulsification

BACKGROUND: The risk of rupture of large abdominal aortic aneurysms (AAAs) remains uncertain. This study aimed to provide data to help decide whether or not to operate on high-risk patients. METHODS: Clinicians were asked to refer all patients with an AAA, even if unfit or elderly. One hundred and ninety-two patients with an intact AAA of 5 cm or greater in diameter were seen in 9 years; 59 had no elective operation and follow-up data were available for 57 at a minimum of 2 years. Initial AAA diameters were 5.0-5-9 cm (n=25) and 6.0 cm or more (n=32). Survival curves were constructed for both groups. RESULTS: At the end of the study 50 of 57 patients had died. Median survival was 18 (range 1-90) months. Twenty (35 per cent) suffered rupture at a median interval of 18 (range 1-38) months. The risk of rupture within 3 years was 28 (95 per cent confidence interval 12-49) per cent for 5.0-5.9-cm AAAs and 41 (24-59) per cent for AAAs of 6 cm or greater. In 133 elective AAA operations in fit patients the 30-day mortality rate was 3 per cent. CONCLUSION: The risk of rupture within 3 years of diagnosis of an AAA of 5 cm or greater exceeds the expected operative mortality rate for fit patients. However, the majority of patients unfit for surgery died from other causes, and only a few would have benefited from aneurysm repair.