Abdominal Aortic Aneurysm Procedures Research Articles

Creation of Murine Experimental Abdominal Aortic Aneurysms with Elastase

Transient intraluminal infusion of porcine pancreatic elastase into the infrarenal segment of the abdominal aorta is the most widely used animal model of abdominal aortic aneurysm (AAA) ever since it was first described in rats by Anidjar and colleagues.(1) The rationale for its development was based on the disrupted nature of elastin observed in AAAs. This rat model has been modified to produce AAAs in the infrarenal aortic region of mice.(2) The model has the ability to add broad insight into the pathobiology of AAA due to the emergence of numerous transgenic and gene knockout mice. Moreover, it is a viable platform to test potential therapeutic agents for AAA. In this video, we demonstrate the elastase infusion AAA procedure used in our laboratory. Mice are anesthetized using 2.5% isoflurane, and a laparotomy is performed under sterile conditions. The abdominal aortais isolated with the assistance of an operating stereomicroscope (Leica). After placing temporary ligatures around the proximal and distal aorta, an aortotomy is created at the bifurcation with the tip of a 30-gauge needle. A heat-tapered segment of PE-10 polyethylene tubing is introduced through the aortotomy and secured. The aortic lumen is subsequently perfused for 5-15 minutes at 100 mm Hg with saline containing type I porcine pancreatic elastase (4.5 U/mL; Sigma Chemical Co.). After removing the perfusion catheter, the aortotomy is repaired without constriction of the lumen.

Concomitant Colorectal Cancer and Abdominal Aortic Aneurysm: Evolution of Treatment Paradigm in the Endovascular Era

Although the incidence of patients presenting with concomitant colorectal cancer (CRC) and abdominal aortic aneurysm (AAA) is low, current treatment strategies in patients with both lesions remains controversial. Given recent advances in endovascular aortic aneurysm repair (EVAR), we sought to analyze the surgical outcomes of patients with concomitant CRC and AAA. A retrospective chart review was performed on all patients with CRC and AAA between December 1984 and July 2007. A total of 108 patients with concomitant CRC and AAA were identified. Forty-six patients presented with symptomatic or obstructing CRC, which was treated with colectomy followed by either open AAA repair (n=35, group A) or EVAR (n=11, group B). Thirty-eight patients underwent either open AAA (n=26, group C) or EVAR (n=12, group D) first, followed by staged CRC resection. Eight patients underwent combined CRC and open AAA repair (group E). The time delays after CRC resection to AAA repair in groups A and B were 42 and 35 days (NS), respectively. The time delays after open AAA or EVAR procedures before CRC resection in groups C and D were 115 days and 12 days (p < 0.0001), respectively. Two patients in group B developed sigmoid ischemia after EVAR and were treated with sigmoid resection. Increased perioperative morbidity and mortality rates were noted in group C (p < 0.002). In patients with concomitant colorectal cancer and AAA, the symptomatic lesion should be a treatment priority. Because EVAR results in early recovery and a shorter convalescence compared with open aneurysmorrhaphy, this modality offers potential treatment benefits in patients with suitable anatomy who have concomitant CRC. But EVAR treatment should be offered with caution because of the risk of sigmoid ischemia caused by inferior mesenteric artery occlusion.

Surgical Treatment Result of Abdominal Aortic Aneurysm in Behçet’s Disease

Objective We report our surgical treatment results of abdominal aortic aneurysm (AAA) in Behçet’s disease patient. Materials and methods Between September 1998 and June 2006, the authors have performed 21 procedures for AAA in 12 patients with Behçet’s disease. Male to female sex ratio was 3:1 and mean age was 34 years old. Behçet’s disease was diagnosed clinically using criteria of International Study Group for Behçet’s Disease (1990). Retrospective analysis was made. Results There were six infrarenal, five suprarenal, and one double (suprarenal and infrarenal)AAA. Six graft interposition, six patch closure, and one stent-graft insertion were performed (one graft interposition and one patch closure were simultaneously performed for double AAA). Eight recurrent aneurysms were noted in six (50%) patients. Four stent-graft insertion, two patch closures, one graft interposition and one explothoracotomy only were performed for recurrent aneurysms. Overall recurrence rate of 21 procedures was 38.1%; 14.3% for graft interposition, 62.5% for patch closure, and 40% for stent-graft insertion. Conclusion Though the resection and graft interposition is technically difficult in many occasions, it should be considered as the procedure of choice for abdominal aortic aneurysm in Behçet’s disease. Endovascular interventions may be one of the treatment modality but the result needs further long-term follow-up.

Surgical Treatment Result of Abdominal Aortic Aneurysm in Behçet's Disease

We report our surgical treatment results of abdominal aortic aneurysm (AAA) in Behçet's disease patient. Between September 1998 and June 2006, the authors have performed 21 procedures for AAA in 12 patients with Behçet's disease. Male to female sex ratio was 3:1 and mean age was 34 years old. Behçet's disease was diagnosed clinically using criteria of International Study Group for Behçet's Disease (1990). Retrospective analysis was made. There were six infrarenal, five suprarenal, and one double (suprarenal and infrarenal)AAA. Six graft interposition, six patch closure, and one stent-graft insertion were performed (one graft interposition and one patch closure were simultaneously performed for double AAA). Eight recurrent aneurysms were noted in six (50%) patients. Four stent-graft insertion, two patch closures, one graft interposition and one explothoracotomy only were performed for recurrent aneurysms. Overall recurrence rate of 21 procedures was 38.1%; 14.3% for graft interposition, 62.5% for patch closure, and 40% for stent-graft insertion. Though the resection and graft interposition is technically difficult in many occasions, it should be considered as the procedure of choice for abdominal aortic aneurysm in Behçet's disease. Endovascular interventions may be one of the treatment modality but the result needs further long-term follow-up.

Implications of Problematic Access in Transluminal Endografting of Abdominal Aortic Aneurysm

Despite careful preoperative assessment, problematic access to the abdominal aorta for transluminal endografting (TE) of abdominal aortic aneurysm (AAA) is sometimes encountered. This study identifies preoperative risk factors predictive of problematic access and determines the impact of problematic access on outcomes. Three hundred twenty-one consecutive TE procedures for AAA were divided into two groups: group A, which had access problems (n = 74), and group B, which had none (n = 247). Logistic regression analysis of risk factors showed that (i) a pulmonary risk score of 3 (P <.001; odds ratio, 11.2), (ii) a hyperlipidemia score of 3 (P =.004; odds ratio, 2.6), and (iii) a small body (short height with low weight, P =.003; odds ratio, of 4.2) were independent risk factors for problematic access. Outcomes compared included rates of perioperative mortality, aborted procedure, surgical conversion, major complication, limb complication, and endoleak. The perioperative mortality rate was higher in group A (6.8% vs 1.2%; P =.018) and procedures were more likely to be aborted in patients in group A (12.2% vs 0%; P <.001). Rates of surgical conversion, major complication, and limb complication were not different between the two groups. The endoleak rate was higher in group B (10.8% vs 26.7%; P =.004). Logistic regression analysis showed that problematic access was an independent risk factor (P =.004; odds ratio, 12.0) for perioperative mortality. Moderate to severe chronic obstructive pulmonary disease and hyperlipidemia, both risk factors for atherosclerosis, were related to problematic access in this series. Small body size was another factor related to problematic access. Problematic access was an independent risk factor for perioperative mortality.

The Low Incidence of Surgery for Non-Cardiac Vascular Disease in UK Asians may be Explained by a Low Prevalence of Disease

Firstly, to compare rates of surgery for non-cardiac vascular disease in Caucasians and Asians and secondarily to assess the prevalence of peripheral arterial disease (PAD) and abdominal aortic aneurysm (AAA) in the male UK Asian population. Analysis of a prospective database followed by an epidemiological survey of 100 unselected Pakistani males, in which demographic and anthropometric data were collected alongside aortic ultrasonography and measurement of ankle: brachial pressure index (ABPI). Although 14.1% of our catchment area is Asian, after correction for age, they only accounted for 64/2268 (2.8%) of procedures for PAD and AAA. Specifically, Asians were 10 times less likely to undergo AAA repair and 3 times less likely to undergo procedures for lower limb peripheral bypass, amputation and endovascular intervention. In the epidemiological study, 26 subjects had a significant history of ischaemic heart disease, 21 were diabetic, 32 had hypertension and 60 were current or ex-smokers. Median aortic diameter [IQR] was 17.6 mm [16.3-19.1 mm] and no subject had an AAA. In 200 limbs, median ABPI [IQR] was 1.12 [1.04-1.21]. Only 2 patients had an ABPI < 0.9. Despite a high prevalence of cardiovascular risk factors and ischaemic heart disease, the prevalence of PAD and AAA is much lower than would have been expected in an age- and sex-matched Caucasian population. These data suggest that the reduced incidence of surgery for PAD and AAA in UK Asians is due to a low prevalence of disease.

Simple Standard Technique for Catheterization of the Short Stub Leg of Modular Aortic Endografts and Confirmation of Coaxial Guidewire Positioning

ObjectiveTo describe our experience of a technique for cannulation of the short limb of modular devices and confirmation of coaxial positioning, in endovascular treatment of abdominal aortic aneurysms. MethodsIn 60 consecutive patients with abdominal aortic aneurysms treated with modular endografts, a standard short leg cannulation system was employed. This system includes insertion of a long sheath through the contralateral common femoral artery over a previously inserted guidewire. After the deployment of the main bifurcated body of the device, a second flexible guidewire via the same long sheath is used for catheterization of the short stub leg. The successful cannulation is confirmed by performing the simple test of advancing the sheath over the two guidewires. ResultsThe short stub leg catheterization was successful in all cases, followed by proper placement of the contralateral iliac limb. ConclusionThe ‘two wires via the same long sheath system’ is a simple and reliable technical step for the accurate placement of the contralateral iliac limb as part of the endovascular repair of abdominal aortic aneurysm procedure.

Simple Standard Technique for Catheterization of the Short Stub Leg of Modular Aortic Endografts and Confirmation of Coaxial Guidewire Positioning

Objective To describe our experience of a technique for cannulation of the short limb of modular devices and confirmation of coaxial positioning, in endovascular treatment of abdominal aortic aneurysms. Methods In 60 consecutive patients with abdominal aortic aneurysms treated with modular endografts, a standard short leg cannulation system was employed. This system includes insertion of a long sheath through the contralateral common femoral artery over a previously inserted guidewire. After the deployment of the main bifurcated body of the device, a second flexible guidewire via the same long sheath is used for catheterization of the short stub leg. The successful cannulation is confirmed by performing the simple test of advancing the sheath over the two guidewires. Results The short stub leg catheterization was successful in all cases, followed by proper placement of the contralateral iliac limb. Conclusion The ‘two wires via the same long sheath system’ is a simple and reliable technical step for the accurate placement of the contralateral iliac limb as part of the endovascular repair of abdominal aortic aneurysm procedure.

The Operative Procedure for Abdominal Aortic Aneurysm after Double Stoma

The Operative Procedure for Abdominal Aortic Aneurysm after Double Stoma

A personal experience with factors influencing survival after elective open repair of infrarenal aortic aneurysms

To investigate risk factors that influence survival after open abdominal aortic aneurysm (AAA) repair in all elective patients treated by a single surgeon at a tertiary referral center. The series includes 855 asymptomatic infrarenal AAAs in 732 men (86%) and 123 women with median ages of 69 and 71 years, respectively. Noninvasive myocardial imaging (n = 325), coronary arteriography (n = 418), or both were performed before surgery in 687 patients (80%), and 100 patients (15%) underwent preliminary coronary artery bypass grafting (n = 78) or percutaneous transluminal coronary angioplasty (n = 22) before their AAA procedures. Survival was assessed by using logistic regression analysis, proportional hazards models, and Kaplan-Meier estimations. The operative mortality rate was 2.5%, ranging only from 1.8% to 2.8% since 1980. Late survival rates (70% at 5 years, 36% at 10 years, and 16% at 15 years) also remained remarkably similar during five arbitrary intervals comprising the entire study period. On multivariable analysis, overall mortality rates were adversely affected by older age (P < .001), increased creatinine levels (P < .001), straight aortic replacement grafting (P < .001), larger aneurysm diameter (P = .036), and chronic obstructive pulmonary disease (P = .012). The risk for any early or late death was favorably influenced by preliminary coronary artery bypass grafting or percutaneous transluminal coronary angioplasty (hazard ratio, 0.76; 95% confidence interval, 0.59-0.98; P = .035) even when a separate multivariable model was fit to accommodate nine other patients who also had preliminary coronary intervention but developed symptomatic AAAs before elective repair could be performed (hazard ratio, 0.78; 95% confidence interval, 0.61-0.99; P = .044). Patient age and medical risk factors determine survival after open AAA repair to a very similar degree irrespective of the era when the operation is performed. In this particular series, preliminary coronary intervention seemed to benefit patients with severe coronary artery disease.

04/01114 Presumed joint probability density function model for turbulent combustion: Guo, Z. M. et al. Fuel, 2003, 82, (9), 1091–1101

Interventional surgical instrument localization is a crucial component of minimally invasive surgery. Image guided surgery researchers are investigating devices broadly categorized as surgical localizers to provide real-time information on the instrument’s 3D location and orientation only. This paper describes the implementation and in vitro evaluation of a prototype real-time nonimaging ultrasound-based catheter localizer system towards use in abdominal aortic aneurysm procedures. The catheter-tip is equipped with a single element ultrasound transducer which is tracked with an array of seven external single element transducers. The performance of the system was evaluated in a water tank and additionally in the presence of pork belly tissue and also a nitinol-dacron stent graft. The mean root mean square errors were respectively 1.94 ± 0.06, 2.54 ± 0.31 and 3.33 ± 0.06 mm. In addition, this paper illustrates errors induced by transducer aperture size and suggests a method for aperture error compensation. Aperture compensation applied to the same experimental data yielded mean root mean square errors of 1.05 ± 0.07, 2.42 ± 0.33 and 3.23 ± 0.07 mm respectively for water; water and pork; and water, pork and stent experiments. Lastly, this paper presents a video showing free-hand movement of the catheter within the water tank with data capture at 25 frames per second.

What are the 1-year mortality rates for carotid endarterectomy (CEA) and abdominal aortic aneurysm (AAA) repair?

Introduction: Most quality of care studies that have analyzed administrative databases have only been able to examine inpatient mortality—which may be a limitation for procedures whose inpatient mortality rates are low. In response, some researchers have examined longer term mortality outcomes (e.g. 30-day), but the available databases only pertain to non-representative segments of the population (i.e. Medicare patients, or Veterans), or cancer registries. In this study, we use a newly developed database to examine the 1-year mortality rates for two vascular surgery procedures. Importantly, the data is population-based, and therefore generalizable. Methods: The OSHPD database (1995–1999), which reports all California inpatient discharges, was linked to the State Death File in order to study mortality outcomes beyond hospital discharge. CEA and AAA procedures were identified by ICD-9 codes and the rates of inpatient and 1-year mortality were assessed. Analyses were performed for each procedure, as well as for elective and emergent cases. Results: For all CEA procedures (n = 44601), the inpatient and 1-year mortality rates were 0.8% and 5.8%, respectively. For emergent cases, the inpatient and 1-year mortality rates were 1.57% and 9.19% (which represents a 5.8-fold increase), while that for elective cases were 0.5% and 5.4% (a 9.7-fold increase). Finally, the CEA inpatient mortality rate for all patients accounts for only 14% of all CEA deaths at 1 year. For all AAA procedures, (n = 16114), the inpatient and 1-year mortality rates were 12.8% and 18.8%. The inpatient and 1-year mortality rates for emergent cases were 28% and 37.1% (a 1.3-fold increase), while for elective cases, they were 4.5% and 9.7%, respectively (a 2.15-fold increase). Contrary to CEA procedures, the AAA inpatient mortality rate for all-comers accounts for 68% of the AAA deaths at 1 year. Conclusions: Our study uses a novel database linkage and reports inpatient and 1-year mortality rates for two common vascular surgical procedures (i.e. CEA and AAA). This analysis provides meaningful data because of the ability to examine outcomes beyond hospital discharge. Future studies will examine the longer-term mortality rates of other common surgical procedures.

Population-based record linkage study of the incidence of abdominal aortic aneurysm in Western Australia in 1985-1994.

The incidence of abdominal aortic aneurysm (AAA) has increased steadily during the past 30 years. Trends in the incidence and surgical intervention for AAA in Western Australia were reviewed for the interval 1985-1994. A population-based health database was used to link morbidity and mortality records of all patients aged 55 years or more who died from rupture or were admitted and treated surgically for AAA. Three groups were separated for analysis: patients with a ruptured AAA, those admitted for elective repair and those admitted as an emergency with an acute (non-ruptured) aneurysm. There was a decline in the incidence of both emergency and elective procedures for AAA after 1992. While the mortality rate from ruptured AAA has also fallen since 1991, the overall case fatality rate for ruptured AAA has fallen by only 1.3 per cent (from 80.7 to 79.3 per cent). The decline in mortality rate and emergency procedures may result from a fall in the incidence of ruptured AAA, due to an increasing rate of elective surgery before 1992. The decline in elective procedures from 1992 may be due to a fall in the prevalence of AAA owing to high rates of elective surgery, or to a fall in the incidence of the disease itself.

Durability of benefits of endovascular versus conventional abdominal aortic aneurysm repair

Purpose: Endovascular abdominal aortic aneurysm (AAA) repair is reported to result in less initial patient morbidity and a shorter hospital length of stay (LOS) when compared with conventional AAA repair. We sought to examine the durability of this result during the intermediate follow-up interval. Methods: The records of all admissions for all patients who underwent AAA repair during a 26-month interval were reviewed. Results: Three hundred thirty-seven (337) patients underwent procedures to repair AAAs (163 open and 174 endovascular). Endovascular procedures were performed with a variety of devices (Talent, 108; Ancure, 36; AneuRx, 26; Zenith, 2; and Cordis, 2) and configurations (141 bifurcated and 33 aortomonoiliac). The mean follow-up period was 10.6 months (endovascular repair) and 12.3 months (open repair). LOS did not significantly vary by device (P =.24 to P =.92) or configuration (P =.24). The initial median LOS for procedures was significantly shorter (P =.009) for endovascular repairs (5 days) than for open procedures (8 days). However, the patients who underwent endovascular repair were more likely to be readmitted during the follow-up interval when compared with patients who underwent open procedure. The readmission-free survival rate after AAA repair at 12 months was 95% for patients for open AAA repair versus 71% for patients for endovascular repair (P <.001). If the total hospital days were compared, including the initial and all subsequent AAA-related admissions, there was no significant difference for mean LOS for patients who underwent endovascular versus open AAA procedures (11 days versus 13.6 days; P =.21). The patients for endovascular AAA repair most commonly needed readmission for treatment of endoleak (n = 31), wound infection (n = 12), and graft limb thrombosis (n = 9). Although women had similar LOS to men for endovascular repair (P =.44), they had longer initial LOS for open AAA repair (15 versus 10 days; P =.03). After endovascular repair, women were more likely than men to be readmitted by 12 months (51% versus 71% readmission-free survival rate; P =.03) and they had longer LOS on readmission (13.2 versus 5.2 days; P =.006). No gender differences were identified for patients after open AAA repair regarding readmission-free survival rate (P =.09) or LOS on readmission (P =.98). Conclusion: Although initial LOS was shorter for the patients who underwent endovascular as compared with conventional AAA repair, this advantage was lost during the follow-up interval because of frequent readmission for the treatment of procedure-related complications, chiefly endoleak. These readmissions frequently involved the performance of additional invasive procedures. Gender differences existed regarding LOS and the likelihood of complications after open and endovascular AAA repair. (J Vasc Surg 2002;35:222-8.)

Ruptured abdominal aortic aneurysm and quality of life.

This study was undertaken to examine the community hospital experience in managing ruptured abdominal aortic aneurysm, and to assess the quality of life in survivors of the abdominal aortic aneurysm procedure. Study parameters included a retrospective chart review with prospective follow-up at a 369-bed, university-affiliated, community teaching hospital. Eighty-one consecutive patients undergoing surgery for ruptured abdominal aortic aneurysm between 1991 and 2000 were included. Main outcome measures included mortality and quality of life, as assessed by the SF-36 health survey. The overall perioperative mortality rate was 34.6%, significantly less (p < 0.005) than the 50% mortality rate reported in the literature. Predictor variables significantly related to mortality were age (p < 0.002), preoperative creatinine (p < 0.026), use of suprarenal clamp (p < 0.0001), acute renal failure (p < 0.0001), myocardial infarction (p < 0.0001), respiratory failure (p < 0.0001), and tobacco use (p < 0.05). Multiple regression analysis found that three predictor variables--myocardial infarction, respiratory failure, and use of a suprarenal clamp--predicted 25% of the variability in mortality (p < 0.0001). The quality-of-life analyses showed that the majority of the patients for whom follow-up data could be obtained (n = 26), reported the same or better quality of life compared to SF-36 norms for age-matched individuals. Results from this community hospital sample suggest that ruptured abdominal aortic aneurysm repair can be accomplished in this setting with an acceptable survival rate, and subsequent quality of life that meets or exceeds that of an age-matched sample.

Mortality rates from ruptured abdominal aortic aneurysms in England

Abstract Background Over the past 10 years significant advances have been made in understanding the natural history and pathophysiology of aortic aneurysm disease. Despite a rapid improvement in alternative repair techniques, surgery for abdominal aortic aneurysm (AAA) remains the standard method of treatment. The aim of this study was to evaluate the efficacy of this treatment at a national level. Methods Data for elective and emergency AAA procedures performed in England between 1989 and 1998 were obtained from the Department of Health Hospital Episode Statistics. Data for deaths secondary to ruptured and non-ruptured AAA in England for the same period were obtained from the Office of National Statistics. All figures represent age-adjusted incidence per 100 000 population. Results The rise in elective and emergency AAA repair rates affected mainly men rather than women. The rise in death rates from ruptured AAA was 30·3 per cent in women and 2·0 per cent in men. Conclusion Despite a considerable increase in elective AAA repair procedures in England, deaths from ruptured AAA continue to rise. These findings highlight the need for an efficient national strategy for improving the outcome of patients with AAA.

Elevated levels of soluble tumor necrosis factor receptors are associated with increased mortality rates in patients who undergo operation for ruptured abdominal aortic aneurysm

Purpose: Elevated levels of soluble tumor necrosis factor receptors (sTNF-Rs) are associated with multiple organ failure and increased mortality rates in critically ill patients. Paradoxically, experimental data suggest exogenous sTNF-Rs may improve outcome in patients who undergo elective abdominal aortic aneurysm (AAA) repair. This study examines, for the first time, changes in sTNF-R levels during repair of ruptured and nonruptured AAA.Methods: Sixteen patients who underwent surgical procedures for ruptured AAA and 10 patients who underwent surgical procedures for nonruptured AAA were studied. Levels of sTNF-Rs p55 and p75 were measured before the operation and immediately before and 5 minutes, 6 hours, and 24 hours after aortic clamp release.Results: When compared with nonruptured AAA, levels of sTNF-R p55 were significantly higher in ruptured AAA 5 minutes (P < .02) and 24 hours after aortic clamp release (P < .05). Levels of sTNF-R p75 were significantly higher in ruptured AAA before (P < .05), during (P < .001), and after the surgical procedure (P < .01). Six hours after aortic clamp release, sTNF-R p75 levels were significantly higher in nonsurvivors of ruptured AAA when compared with survivors (P < .05) and patients who underwent surgical procedures for nonruptured AAA (P < .01).Conclusion: Ruptured AAA repair is associated with increased sTNF-R expression. Furthermore, elevated levels of sTNF-R p75 are associated with increased postoperative mortality rates.

Elevated levels of soluble tumor necrosis factor receptors are associated with increased mortality rates in patients who undergo operation for ruptured abdominal aortic aneurysm

Elevated levels of soluble tumor necrosis factor receptors (sTNF-Rs) are associated with multiple organ failure and increased mortality rates in critically ill patients. Paradoxically, experimental data suggest exogenous sTNF-Rs may improve outcome in patients who undergo elective abdominal aortic aneurysm (AAA) repair. This study examines, for the first time, changes in sTNF-R levels during repair of ruptured and nonruptured AAA. Sixteen patients who underwent surgical procedures for ruptured AAA and 10 patients who underwent surgical procedures for nonruptured AAA were studied. Levels of sTNF-Rs p55 and p75 were measured before the operation and immediately before and 5 minutes, 6 hours, and 24 hours after aortic clamp release. When compared with nonruptured AAA, levels of sTNF-R p55 were significantly higher in ruptured AAA 5 minutes (P <.02) and 24 hours after aortic clamp release (P <.05). Levels of sTNF-R p75 were significantly higher in ruptured AAA before (P <.05), during (P <.001), and after the surgical procedure (P <.01). Six hours after aortic clamp release, sTNF-R p75 levels were significantly higher in nonsurvivors of ruptured AAA when compared with survivors (P <.05) and patients who underwent surgical procedures for nonruptured AAA (P <.01). Ruptured AAA repair is associated with increased sTNF-R expression. Furthermore, elevated levels of sTNF-R p75 are associated with increased postoperative mortality rates.

Realistic Expectations for Patients with Stent-graft Treatment of Abdominal Aortic Aneurysms. Results of a European Multicentre Registry

Objective: the outcomes for patients after endovascular treatment of abdominal aortic aneurysm (AAA) are determined primarily by the endpoints of death and endoleaks, the latter representing continued risk of rupture. The data of a multicentre registry were analysed with regard to the early outcome of stent-graft procedures for AAA and the complications associated with this treatment. In addition, the results during follow-up were analysed by determining mortality and endoleak development as separate endpoints and as a combined endpoint defined as endoleak-free survival. Setting: 38 European institutions of Vascular Surgery collaborating in a multicentre registry project. Patients and methods: 899 patients with AAA underwent between May 1994 and March 1998 elective endovascular repair (818 men and 81 women; mean age 69 years). 80 (8.9%) of the patients had medical conditions that excluded them from open repair. 818 (91%) of patients had a bifurcated device, 63 (7%) had a straight tube graft, and only 18 (2%) had an aorto-uni-iliac device. Clinical examination and contrast-enhanced computed tomography was performed at fixed follow-up intervals to assess increase or decrease of the maximum transverse diameter (MTD). Endoleaks observed at follow-up were discriminated into persistent endoleak andtemporary endoleak . The latter is defined as single time observed endoleaks or with two or more negative imaging studies between observed endoleaks. Life-table analyses were used to calculate the rates of freedom-from-endoleak (no endoleak at any time), freedom-from-persistent endoleak (no persistent endoleak), patient survival , andpersistent-endoleak-free-survival . Results: the median follow-up of this patient series was 6.2 months. The ratio between observed and expected follow-up data was 82% for the overall follow-up period. However, at 18 months of follow-up this rate was only 45%. The number of patients followed during this period was sufficient to allow statistically meaningful assessment. The MTD in patients with temporary endoleaks demonstrated a significant decrease at 6 to 12 months compared to preoperative values (mean 57 and 53 respectively, p =0.004). In patients with persistent endoleaks there was no change between the preoperative and 6-month MTD (mean 57 and 60 mm respectively). At 6 and 18 months freedom-from-endoleak was 83% and 74% and freedom-from-persistent endoleak was 93% and 90%, respectively. The 18-month cumulative patient survival was 88% and the main outcome measure, the persistent endoleak-free-survival was 79%. Conclusions: the MTD decreases in patients with temporary endoleak, but not in patients with persistent endoleak. Therefore, the use of the rate of freedom-from-persistent endoleak, reflecting absence of persisting endoleaks to estimate the prognosis with regard to the AAA, is justified. Determining persistent endoleak-free survival appears a rational approach to provide a realistic outlook for patients with stent-grafted AAA. The observed 18-month endoleak-free survival reflects a satisfactory mid-term result.

Contracts: Third Circuit Upholds Limited Immunity of Peer Review Actions Under HCQIA

The U.S. Court of Appeals for the Third Circuit held, in Brader v. Allegheny General Hospital, 167 E3d 832 (3rd Cir. 1990), that the Health Care Quality Improvement Act (HCQIA), 42 U.S.C. §§ 11101-11152 (1986), shields a Pennsylvania hospital from a surgeon's claims of contract violations.The plaintiff, Alan Brader, M.D., joined Allegheny General Hospital's (AGH) provisional medical staff in July 1988. During the next two years, he performed several abdominal aortic aneurysm (AAA) repairs and various other operations. Several of Brader's patients sustained serious injuries or died during surgery from complications. In 1989, Brader's supervisors, Drs. Daniel Diamond and George Magovern, met to discuss their dissatisfaction with Brader's behavior, his departures from hospital protocol, as well as his disruptive presence in the hospital. From 1989 to 1990, Brader continued to perform surgical procedures on incoming patients, and he continued to violate hospital notification protocol and lost a patient during surgery. In spring 1990, the Quality Assurance Department (QAD) compiled data on AAA procedures for the hospital's physicians.