Expansion rates and outcomes for the 3.0-cm to the 3.9-cm infrarenal abdominal aortic aneurysm

OBJECTIVE: This study was performed for the determination of the expansion rates and outcomes and for recommendations for the surveillance of the 3.0-cm to 3.9-cm abdominal aortic aneurysm (AAA). DESIGN: The study was observational with data from patients screened with ultrasound scanning for AAA at five Veterans Affairs Medical Centers for enrollment in the Aneurysm Detection and Management Trial. The eligibility requirements included: AAA from 3.0 cm to 3.9 cm in diameter and at least one repeat ultrasound scan more than 90 days after the initial screening. Patients also completed a questionnaire for demographic data and the determination of the presence of risk factors associated with AAA. The study endpoints included: 1, both mean and median expansion rates; 2, moderate expansion (>4 mm/year); 3, no expansion; 4, all causes of death; 5, AAA rupture; 6, expansion to 4 cm or more; 7, expansion to 5.0 cm or more; and 8, operative repair. RESULTS: Ultrasound scan screening results identified 1445 patients with 3.0-cm to 3.9-cm AAAs. Seven hundred ninety men met the ultrasound scan criterion of having at least two ultrasound scan studies during the study period, and these 790 men were used for this study. Mean AAA size was 3.3 cm, with an average follow-up period of 3.89 +/- 1.93 years. The median expansion rate was 0.11 cm/year. Expansion rates were significantly different (P <.001) between 3.0-cm and 3.4-cm cm AAA and 3.5-cm and 3.9-cm AAA. There were no reported AAA ruptures during the study period, although cause of death data were available in only 43% of the patients. Few 3.0-cm to 3.9-cm AAAs expanded to 5.0 cm or more during the study period. The patients with 3.0-cm to 3.9-cm AAAs who underwent operative repair during the study period were younger, had larger initial AAA diameters, and had more rapid expansion rates. CONCLUSION: AAAs of 3.0 cm to 3.9 cm expanded slowly, did not rupture, and rarely had operative repair or expanded to more than 5.0 cm in our study of male patients. Expansion rates and the incidence rate of operative repair are more common in the 3.5-cm to 3.9-cm AAA when compared with the 3.0-cm to 3.4-cm AAA.     

Four-year follow up of patients with untreated abdominal aortic aneurysms

BACKGROUND: The data in the literature are still controversial describing the outcome of patients not treated for a large abdominal aortic aneurysm (AAA) especially with significant comorbidities. We followed up patients trying to establish their long-term outcome. METHOD: Since 1998, we have prospectively followed all patients referred to our department with AAA. A retrospective analysis was carried out selecting all patients who had an AAA larger than 5 cm, and who declined or were declined for operative repair between February 1998 and November 2001. RESULTS: One hundred and eleven patients were included in the present study. There were 78 men and 33 women. The mean age was 80 years. At the end of the study, 65 patients (59%) were deceased. Ruptured aneurysm occurred in 27 patients (median time to rupture = 14 months) with one patient surviving an emergency repair. Thirty-nine patients died from unrelated illnesses. In the 5-5.9 cm AAA group (n = 58), out of 31 deceased patients, five (16%) have died of ruptured AAA. In the 6 cm and larger AAA group (n = 53), out of 34 deceased patients, 21 (62%) have died of ruptured AAA. There was no significant difference in survival between patients with AAA below and above 6 cm in diameter (P = 0.15). CONCLUSION: In the presence of significant comorbidities, most patients with AAA less than 6 cm died from unrelated illnesses. In the larger AAA group, the likelihood of death from AAA rupture or unrelated illnesses is almost equal.     

ABDOMINAL AORTIC ANEURYSM AND ASSOCIATED COLORECTAL CARCINOMA: A MANAGEMENT PROBLEM

The increasing age of the population has led to the more common occurrence of multi-organ disease. Colorectal cancer (CRC) and abdominal aortic aneurysm (AAA) in the same patient is a difficult management problem. Over 10 years, 23 patients with CRC and AAA were treated at Concord Hospital. The management and outcome of these patients was reviewed to identify an optimum plan for patients with both conditions. The average age of patients was 71 years, ranging from 52 to 90 years. There was only one female patient in the series. In 19 of the patients, the AAA and CRC were synchronous, while in the other four patients the AAA and CRC were remote events. Within the group of patients with synchronous AAA and CRC, 12 had the diagnosis of both conditions made pre-operatively. However, in seven cases an unexpected AAA or CRC was found at operation for the other condition. Sixteen patients underwent resection of the CRC, while only eight underwent repair of the AAA. There were three deaths following CRC resection, two following AAA resection, and one following simultaneous CRC resection and AAA repair. Two of 10 patients with large (> 6cm) AAA, who underwent CRC resection, ruptured the AAA in the postoperative period. A further patient ruptured 10 months following CRC resection. Colorectal cancer was given priority over AAA when these conditions were found simultaneously. The present study suggests that a large AAA (> 6cm) should be either given preferential treatment, or resected simultaneously, in view of the high risk of rupture.     

Laparoscopy-assisted aneurysm resection as a minimal invasive alternative in patients unsuitable for endovascular surgery

OBJECTIVE: So far, endovascular surgery has been the only minimal invasive way to treat patients with abdominal aortic aneurysms (AAAs). With hand-assisted laparoscopic surgery (HALS), laparoscopic transperitoneal endoaneurysm repair can be performed through a 6-cm mini-incision only. We wanted to evaluate whether this laparoscopic technique can be offered as a minimal invasive alternative in patients unsuitable for endovascular AAA repair. MATERIAL AND METHODS: Forty patients were referred for endovascular AAA repair. Three patients had to be excluded from the study. Endovascular AAA exclusion was finally performed in 13 patients. Laparoscopic AAA resection was performed in 24 patients. Hand-assisted laparoscopic surgery with transperitoneal access and endoaneurysm repair was accomplished in all patients unsuitable for an endovascular procedure. The outcome after endovascular repair was compared with the outcome of patients who underwent laparoscopy. RESULTS: In the laparoscopic group, conversion to an open procedure was necessary in one case. One patient in this group died (4.1%) postoperatively. There were four complications in each group. In the endovascular group we had one endoleak type II and one graft thrombosis, which required a reoperation. After endovascular treatment, patients were transferred significantly less frequently to the intensive care unit, and they could resume oral feeding earlier. Mobilization and postoperative hospital stay did not differ significantly between the groups. CONCLUSION: Laparoscopic AAA resection with the use of the technique described can be routinely offered to patients unsuitable for endovascular AAA exclusion with excellent long-term results similar to open surgery. A controlled study is clearly indicated to evaluate the role of laparoscopic techniques in aneurysm surgery.     

Concomitant management of a large abdominal aortic aneurysm and a giant incarcerated inguinal hernia

The optimal therapeutic approach to a patient who has a large incarcerated inguinal hernia and an abdominal aortic aneurysm (AAA) of significant size is controversial. Here we report a case of a patient who presented with a giant incarcerated inguinal hernia who was found to have an 8-cm AAA. Three surgical options were considered: (1) perform open AAA repair first, followed by hernia repair a few weeks later to allow for recovery, (2) perform hernia repair first followed by AAA repair a few weeks later, or (3) perform both simultaneously as a combination procedure. We successfully performed hernia repair first, followed by open AAA repair as a separate procedure at a later date. We believe that a two-stage approach, performing hernia repair first, is the safest approach to surgical repair of an incarcerated hernia in a patient with an asymptomatic AAA that requires open repair.     

A myth exposed: fast growth in diameter does not justify precocious abdominal aortic aneurysm repair.

OBJECTIVES: fast growth of abdominal aortic aneurysm (AAA) diameter is claimed to be an indication for repair. We investigated the validity of this claim. METHODS: between January 1988 and October 2000, 277 patients have had duplex sonography at six-monthly intervals in our aneurysm surveillance programme. During this period fast AAA growth was not an indication for operation in our unit. RESULTS: we identified 63 patients whose aneurysms had grown 0.5 cm or more in 6 months. Thirty-one of the 63 patients had aneurysms measuring 5.5 cm or greater in anterior-posterior diameter after the fast growth and all have been operated on unless deemed not fit due to anaesthetic risk. The remaining 32 patients continued in surveillance for a total of 50 patient years and none had rupture of their aneurysm. The calculated 95% confidence interval for the risk of rupture was 0-6 per 100 patient years. Six patients, who would have been operated on if fast growth had been an indication, have been spared surgery of whom 3 died and 3 became unfit. Nine patients remained in surveillance at the end of the study. CONCLUSION: our data support the view that rapid increase in AAA diameter is not an indication for elective AAA repair.     

Endovascular vs open AAA repair: does size matter?

Since the natural tendency of the aorta is to increase in diameter and tortuosity with age and since abdominal aortic aneurysms (AAAs) increase in diameter and length over time, encroaching on the renal and hypogastric orifices, early repair of AAAs (when > or =4.0 cm) may allow greater applicability of the endovascular option because of more favorable aortoiliac morphology. Patients who present at an older age with larger AAAs should be more likely to be anatomically excluded from endovascular AAA repair. Over a 42-month period, 317 consecutive patients referred with aortoiliac aneurysms (infrarenal AAA > or =4.0 cm) were evaluated by one of the authors (SGL) for endovascular vs open repair based on computed tomography (CT) and angiographic imaging. The 10 anatomic exclusion criteria were those applicable to the Zenith endograft (Cook, Inc), which currently is the most anatomically inclusive of the aortic endografts in commercial use in the United States. Based on their aortoiliac morphology, 212 patients were excluded from endovascular repair and 105 were included as acceptable anatomic candidates. Age, AAA size, and the reason(s) for exclusion were recorded for each patient. By use of Student's t test and logistic and linear regression analyses, the groups were compared by age, AAA size, and age + size. There was no significant difference in patient age or AAA size distribution between the group of patients excluded from endovascular repair based on aortoiliac morphology compared to those who met the inclusion criteria. Patients with small AAAs (4.0-5.4 cm) had similar age distribution as those with large (> or =5.5 cm) AAAs. The majority of patients (87%) were excluded based on proximal aortic neck morphology. The presence of aortoiliac morphology that precludes endovascular repair is independent of patient age or AAA size at presentation. A patient presenting with a small (4.0-5.4 cm) AAA is not more likely to be a candidate for endovascular repair than a patient with a large AAA.     

The risk of rupture in untreated aneurysms: the impact of size,gender, and expansion rate

OBJECTIVE: The purpose of this study was to establish the risk of rupture as related to size of abdominal aortic aneurysm (AAA), gender, and expansion of the aneurysm. METHODS: Between 1976 and 2001, 476 patients with conditions considered unfit for surgery with AAA 5.0 cm or more were followed with computed tomographic scans every 6 months until rupture, surgery, death, or deletion from follow-up. Surgery was performed for rupture (n = 22), improved medical condition (n = 37), increase in size (n = 95), symptoms (n = 17), and other reasons (n = 24). RESULTS: Fifty ruptures occurred during the follow-up period. The average risk of rupture (and standard error) in male patients with 5.0-cm to 5.9-cm AAA was 1.0% (0.01%) per year, in female patients with 5.0-cm to 5.9-cm AAA was 3.9% (0.15%) per year, in male patients with 6.0-cm or greater AAA was 14.1% (0.18%) per year, and in female patients with 6.0-cm or greater AAA was 22.3% (0.95%) per year. CONCLUSION: The risk of rupture in male patients with AAA 5.0 to 5.9 cm is low. The four-time higher risk of rupture in female patients with AAA 5.0 to 5.9 cm suggests a lower threshold for surgery be considered in fit women. The data regarding risk of rupture in patients with AAA 6.0 cm or more may allow more appropriate decision analysis for surgery in patients with unfit conditions with large AAA.     

For debate: concomitant critical coronary arterial disease and abdominal aortic aneurysm--timing of corrective procedures

BACKGROUND: The high prevalence of coronary artery disease (CAD) in patients with abdominal aortic aneurysm (AAA) is responsible for most , 30-day mortality and morbidity in elective repair of AAA. The continuing debate regarding staged or combined surgery for AAA and CAD (coronary artery bypass grafting -CABG) in the small number of patients with critical degrees of both co-morbidities has not had a significant impact on the greater mortality and morbidity when the AAA repair is undertaken using the standard open operation. PATIENTS: We report four cases with these combined pathologies which we have managed over the last 30 months during which time we have developed techniques of endolumenal repair of AAA. CONCLUSIONS: Whilst it is not possible to make firm recommendations regarding management strategy owing mainly to a lack of large series reporting this unusual combination of co-morbidities, the options are debated on the basis of published anecdotal evidence as well as our own case reports. We suggest that if the AAA is non-tender and/or 5.5-8.0 cm, the staged approach is appropriate. If the AAA is tender and/or > 8.0 cm, a combined approach may be a better option in order to avoid the risk of AAA rupture during the interval between the operations. Endolumenal repair of AAA offers a further option for the staged and combined approach, and may be less invasive than the standard open surgery for AAA repair.     

Is preoperative cardiac evaluation for abdominal aortic aneurysm repair necessary?

Purpose: It is reported that 25% to 50% of patients with abdominal aortic aneurysms (AAA) have severe coronary artery disease (CAD) and should undergo an aggressive cardiac workup before AAA repair. In contrast, it has been our policy that patients referred for AAA repairs undergo no cardiac testing before surgery.Methods: This report reviews the last 113 consecutive patients who underwent elective AAA repair by the senior author using this policy. Seventy-four patients (group A) had only an electrocardiogram before surgery. The remaining 39 patients (group B) were referred having already had additional testing that included a thallium stress test (n = 20), echocardiogram (n = 18), multiple gated acquisition (MUGA) scan (n = 3), cardiac catheterization (n = 8), or some combination of these.Results: There was no statistical difference between group A and group B with regard to age, sex, tobacco use or history of coronary artery disease, diabetes mellitus, stroke (CVA), hypertension, peripheral vascular disease, or chronic obstructive pulmonary disease. Group B more commonly had a history of myocardial infarction (41% vs 19%, p < 0.03) and congestive heart failure (23% vs 7%, p < 0.03). During surgery there was no significant differences in blood loss, transfusion requirements, or operative times. There were no myocardial infarctions in group A and two (5.1%) in group B, which was not significantly different. Other complications, such as CVA, renal failure, pulmonary failure, pneumonia, wound infection, and hemorrhage, were not significantly different between the two groups. Postoperative hospital stay was not significantly different. There were three deaths in the entire series (2.7%), and only one in group B was cardiac-related in a patient with known end-stage cardiac disease and a symptomatic 8 cm AAA.Conclusions: These data indicate that most patients with AAA can safely undergo repair with no cardiac workup and that cardiac workup before AAA repair contributes little information that impacts on treatment or final clinical outcome. We conclude that cardiac testing in preparation for AAA repair is not usually necessary and that intraoperative hemodynamic management may be the most important variable in determining outcome. (J Vasc Surg 1997;25:152-6.)     

Repair of large abdominal aortic aneurysm should be performed early after coronary artery bypass surgery

PURPOSE: The surgical repair (coronary artery bypass grafting [CABG]) of symptomatic coronary artery disease (CAD) in patients with co-existent large abdominal aortic aneurysm (AAA) may result in an increased rate of AAA rupture after operation. Simultaneous CABG/AAA repair has been recommended by some surgeons, but with a somewhat higher mortality rate than staged repair. We reviewed the outcome of staged AAA repair that was performed early after CABG in patients with symptomatic coronary disease and AAA. METHODS: The records of all the patients with symptomatic CAD that required CABG with large AAA (greater than 5 cm) were reviewed. In most patients, CABG was performed first, followed by AAA repair within 2 weeks. Patient demographics, severity of coronary disease, AAA size, interprocedure duration, and perioperative morbidity and mortality rates were examined. RESULTS: Between 1991 and 1998, 1105 AAA repairs were performed. Within this group, 30 patients with AAA underwent CABG for symptomatic CAD. Mean AAA size was 6.6 cm (range, 5.0-10.0 cm). The median interprocedure interval between CABG and AAA repair was 11.5 days. There was no in-hospital AAA rupture during this interval. The patient group was comprised of 24 men and 6 women with a mean age of 71 years. There was no operative death after such staged AAA repair, and nonfatal complications occurred in seven patients (23%). During this period, seven patients had AAA rupture when they were sent home after CABG for recovery and intended AAA repair at a later date. CONCLUSION: Staged elective AAA repair may be performed safely and effectively after CABG. Performance of these procedures with a short interprocedure interval may be preferable to the higher complication rate observed after combined procedures.     

Results of surgical therapy and classification of non-ruptured abdominal aortic aneurysms

INTRODUCTION: Surgery for symptomatic aortic abdominal aneurysms (sAAA) is associated with an increased mortality and morbidity compared to asymptomatic aortic aneurysms (aAAA). With the advent of endovascular therapy, an alternative therapeutic modality has become available. Endovascular therapy, however, depends on certain morphologic criteria, whereas open surgery can be performed on any type of AAA. The purpose of this study was to analyse our data of surgical treatment of non ruptured AAA and to identify the amount of patients in whom endovascular therapy would have been possible. METHODS: Retrospective analysis of the medical data of all patients operated upon non ruptured AAA in our department by 3 responsible vascular surgeons from 1995-1999. RESULTS: 225 consecutive patients with a median age of 65 (42-95) years were included in the study. There were 184 (82%) male and 41 (18%) female patients with 143 (63.5%) aAAA and 82 (36.5%) sAAA. Patients with sAAA underwent emergency aneurysm repair and had a significantly increased aneurysm diameter compared to the aAAA, who underwent elective surgical aneurysm repair (6.9 +/- 1.6 cm vs. 6 +/- 1.2 cm; p = 0.002). A total of 11 (4.9%) patients had an inflammatory AAA. Smoking was found to be the only significant increased preoperative risk factor in the group of sAAA compared to aAAA (91 vs. 35 patients; p = 0.008). Morbidity was significantly increased in the patients with sAAA compared to the aAAA (55% vs. 31.5%; p = 0.041) The mortality however did not differ significantly in the two groups (2 vs. 3 patients; p = 0.691). Considering morphological criteria of the AAA, endovascular therapy would have been possible in 59 (26%) patients. However, in 24 (11%) of the 59 patients, endovascular therapy was not feasible because of aortic kinking, heavy calcification of the aneurysm neck, a patent inferior mesenteric artery or atherosclerotic diseased iliac arteries. Consequently, only 35 (15%) patients would have qualified for an endovascular therapy. DISCUSSION: Surgical therapy can be performed in patients with asymptomatic and symptomatic AAA with an equal low mortality. This finding underlines the fact, that surgical therapy still remains the standard therapy for AAA. In addition, in our study only a relative small amount of patients would have qualified for an endovascular therapy.     

Symptomatic sac enlargement and rupture due to seroma after open abdominal aortic aneurysm repair with polytetrafluoroethylene graft: Implications for endovascular repair and endotension

OBJECTIVE: We report 5 patients in whom a symptomatic perigraft seroma developed within the aortic sac, without vascular endoleak, after open repair of an abdominal aortic aneurysm (AAA) with a polytetrafluoroethylene (PTFE) graft. We also discuss possible relationships of this phenomenon to endovascular repair of AAAs. PATIENTS AND METHODS: Over 18 years, 1156 patients underwent repair of an AAA by one of the authors (B.M.B.). Of these, 1084 underwent open repair, 256 with PTFE grafts. Five patients in the PTFE group (2.3%) returned at a mean of 4.5 years with acute abdominal or back pain and enlargement of the aortic sac. Mean diameter of the aneurysms was 5.9 cm preoperatively and 8.1 cm at readmission. There was no evidence of vascular endoleak on computed tomography scans, but 1 patient had a retroperitoneal hematoma. RESULTS: Laparotomy in 4 patients disclosed a seroma containing firm rubbery gelatinous material under tension, histologically identified as amorphous eosinophilic material containing thrombus and degenerate blood cells in all cases. Rupture of the sac was confirmed in the patient with a retroperitoneal hematoma. The sac contents were evacuated and the integrity of the underlying grafts and anastomoses was confirmed before sac reduction, with imbricating sutures, and closure was performed. One patient died at 8 months of an unrelated cause; the other 3 patients remain well at mean follow-up of 12 months. The fifth patient received conservative treatment and remains asymptomatic 3 years after acute presentation. CONCLUSIONS: These findings of sac enlargement without vascular endoleak after open AAA repair are reminiscent of sac enlargement in the absence of endoleak after endovascular AAA repair. This has been referred to as endotension. The comparatively benign outcome in 5 patients with symptomatic sac enlargement, including 2 patients with rupture, after open AAA repair provides data to support a circumspect approach to endotension, especially in patients with asymptomatic disease, which has been reported as occurring in almost half of patients who received a PTFE Excluder endograft.     

Treatment of Type III Endoleak with an Aortouniiliac Stent Graft

The purpose of this study was to present a novel treatment method for repair of a type III endoleak due to separation of modular components of an AneuRx (Medtronic AVE, Sunnyvalle, CA) stent graft as a result of graft kinking. A 73-year-old male had undergone endovascular repair of a 8.2-cm abdominal aortic aneurysm (AAA) 2 years previously. An aortic extender cuff was required to secure the proximal graft. Computed tomographic (CT) follow-up revealed a type III endoleak at 6-month follow-up. Plain radiographs showed separation between the main graft body and the aortic extender cuff. A second custom-made 28 mm × 5.5cm aortic extender cuff was placed to seal the type III endoleak. Follow-up CT showed a persistent endoleak with an increase in AAA size to 10.5 cm. The patient underwent remedial AAA repair with an aortouniiliac endograft placed within the previous stent graft and a femorofemoral bypass. At 3-month follow-up there was no detectable endoleak. This constitutes an alternative endovascular therapy for modular device separation (type-III endoleak) after endoluminal AAA repair in patients who cannot undergo repair with a second bifurcated graft.     

One-stage Surgical Management of Concomitant Abdominal Aortic Aneurysm and Gastric or Colorectal Cancer

One-stage surgical management of concomitant abdominal aortic aneurysm (AAA) and gastric or colorectal cancer should provide certain benefits. We reviewed the records of 21 patients with both AAA and gastric or colorectal cancer who underwent one-stage surgical management. Four had distal gastrectomy, 2 had total gastrectomy, and 5 had abdominoperineal rectal resection transperitoneally; 3 had total gastrectomy transperitoneally and AAA repair extraperitoneally. Two underwent right hemicolectomy and thromboexclusion of the AAA. Two had creation of a temporary ileostomy and implantation of an interposition graft. Two underwent left hemicolectomy, creation of a temporary transversostomy, and implantation of an interposition graft. One had a Hartmann’s procedure and implantation of a bifurcated prosthetic interposition graft for AAA. There were no operative deaths or serious postoperative complications. One patient had colorectal ischemia that resolved with conservative treatment. Eighteen of the 21 patients (85.7%) were alive 10 months to 14 years postoperatively. In conclusion, one-stage surgical treatment of concomitant AAA and gastric or colorectal cancer is well tolerated and can avoid the time, financial costs, and patient anxiety involved in a second operation.     

Optimizing compliance, efficiency, and safety during surveillance of small abdominal aortic aneurysms

BACKGROUND: Outcome data documenting safety for observation of small abdominal aortic aneurysms (AAA 4.0 to 5.4 cm) are lacking outside of large clinical trials but requires near perfect patient compliance. This study describes a clinical pathway for AAA surveillance using a prospective database utilizing a nurse practitioner oversight to provide efficient use of clinic visits while maintaining a high level of patent participation. METHODS: Over a 7-year period (June 1999 through June 2006), 334 patients were enrolled in an AAA surveillance pathway at our academic veterans hospital. To minimize patient travel, clinic visitation was reserved for an initial examination with patient education and for discussion of intervention options in patients demonstrating AAA growth (>5.4 cm or expansion >1 cm/yr) during follow-up. Biannual ultrasound or CT imaging was scheduled and results discussed (after physician review) via telephone or "same day" direct patient contact. An electronic database was used to update patient information and plan follow-up. RESULTS: Compliance with the AAA surveillance pathway was achieved in 98.5% of patients, with only three patients (0.9%) lost to follow-up and two others (0.6%) choosing early repair at civilian institutions. At a mean interval of 29 months (+/-20 mo), surgical repair was performed in 225 (67%) patients by open (n = 143) or endovascular (n = 82) techniques for AAA growth to >5.4 cm (n = 219) or expansion by >1cm/yr (n = 6). One hundred six patients currently remain in surveillance. A single AAA rupture resulting in death occurred during surveillance (0.3%) and perioperative mortality (<60 days) was 0.9% in patients needing intervention for AAA growth. Cumulative aneurysm-related mortality was 0.9% for patients compliant with the AAA surveillance pathway. CONCLUSIONS: Use of a prospectively-maintained surveillance database managed by a non-physician provider with a reliance on telephone contact resulted in a high degree of patient compliance, reduced unnecessary patient travel, and provided practical clinic use. Limited additional resources were needed to implement our pathway and a similar approach may prove useful for large volume hospital, clinic, or practice systems.     

Aortic aneurysms in children and young adults with tuberous sclerosis: report of two cases and review of the literature

Abdominal aortic aneurysms (AAAs) in children and young adults are rare; some have been observed in patients with tuberous sclerosis (TS). We report two cases and review the literature. A 9-year-old girl with TS was diagnosed with a 3-cm calcified AAA, and a 41-year-old man with TS was diagnosed with a 7.5-cm thoracic aortic aneurysm (TAA). Both patients underwent open repair with a tube polyester graft without complication. They are both doing well at 7 and 8 years after surgery. Pathologic evaluation revealed medial atrophy and focal medial disruption in the aortic wall in both patients. With our two cases, 15 patients with TS and aneurysms have been reported; 12 had AAA, and four had TAA (one patient had both). Three AAAs and two TAAs ruptured. Six patients died because of aneurysmal disease. There is an association between TS and aortic aneurysms. Patients should be screened for aortic aneurysms at the time TS is diagnosed and annually thereafter. Because of the high risk of rupture, early elective repair is suggested. New aortic aneurysms after repair may also develop.     

Positron emission tomography (PET) evaluation of abdominal aortic aneurysm (AAA).

BACKGROUND: aneurysmal disease is associated with an inflammatory cell infiltrate and enzymatic degradation of the vessel wall. AIM OF THE STUDY: to detect increased metabolic activity in abdominal aortic aneurysms (AAA) by means of positron emission tomography (PET-imaging). STUDY DESIGN: twenty-six patients with AAA underwent PET-imaging. RESULTS: in ten patients, PET-imaging revealed increased fluoro-deoxy-glucose (18-FDG) uptake at the level of the aneurysm. Patients with positive PET-imaging had one or more of the following elements in their clinical history: history of recent non-aortic surgery (n = 4), a painful inflammatory aortic aneurysm (n = 2), moderate low back pain (n = 2), rapid (> 2;5 mm in 6 months) expansion (n = 4), discovery by PET-scan of a previously undiagnosed lung cancer (n = 3) or parotid tumour (n = 1). Five patients with a positive PET scan required urgent surgery within two to 30 days. Among the 16 patients with negative PET-imaging of their aneurysm, only one had recent non-aortic surgery, none of them required urgent surgery, only two had a rapidly expanding AAA, and in only one patient, PET-imaging revealed an unknown lung cancer. CONCLUSION: these data suggest a possible association between increased 18-FDG uptake and AAA expansion and rupture.     

The cost-effectiveness of early surgery versus watchful waiting in the management of small abdominal aortic aneurysms

Purpose: The purpose of this study was to compare the relative cost-effectiveness of two clinical strategies for managing 4 to 5 cm diameter abdominal aortic aneurysms (AAAs): early surgery (repair 4 cm AAA when diagnosed) versus watchful waiting (monitor AAA with ultrasound size measurements every 6 months and repair if the diameter reaches 5 cm).Methods: We used a Markov decision tree to compute the expected survival in quality-adjusted life years (QALYs) for each strategy, based on literature-derived estimates for the probabilities of different outcomes in this model. We determined hospital costs for patients undergoing elective and emergency AAA repair at our center. With standard methods of cost accounting, we then calculated the additional cost per year of life saved by early surgery compared with watchful waiting (cost-effectiveness ratio, dollars/QALY).Results: Mean hospital costs for elective and emergency AAA repair were $24,020 and $43,208, respectively (1992 dollars). For our base-case analysis (60-year-old men with 4 cm diameter AAAs, with 5% elective operative mortality rate and 3.3% annual rupture rate), early surgery improved survival by 0.34 QALYs compared with watchful waiting, at an incremental cost of $17,404/QALY. Increased elective surgical mortality rate, decreased AAA rupture risk, and increased patient age all reduced the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery.Conclusions: The cost effectiveness of early surgery for 4 cm diameter AAAs in carefully selected patients compares favorably with that of other commonly accepted preventive interventions such as hypertension screening and treatment. With an upper limit of $40,000/QALY as an "acceptable" cost-effectiveness ratio, early surgery appears to be justified for patients 70 years old or younger, if the AAA rupture risk is 3%/year or more and the elective operative mortality rate is 5% or less. Although not a substitute for clinical judgment, this cost-effectiveness analysis delineates the essential tradeoffs and uncertainties in treating patients with small AAAs. (J VASC SURG 1994;19:980–91.)     

In vivo analysis of mechanical wall stress and abdominal aortic aneurysm rupture risk

OBJECTIVE: The purpose of this study was to calculate abdominal aortic aneurysm (AAA) wall stresses in vivo for ruptured, symptomatic, and electively repaired AAAs with three-dimensional computer modeling techniques, computed tomographic scan data, and blood pressure and to compare wall stress with current clinical indices related to rupture risk. METHODS: CT scans were analyzed for 48 patients with AAAs: 18 AAAs that ruptured (n = 10) or were urgently repaired for symptoms (n = 8) and 30 AAAs large enough to merit elective repair within 12 weeks of the CT scan. Three-dimensional computer models of AAAs were reconstructed from CT scan data. The stress distribution on the AAA as a result of geometry and blood pressure was computationally determined with finite element analysis with a hyperelastic nonlinear model that depicted the mechanical behavior of the AAA wall. RESULTS: Peak wall stress (maximal stress on the AAA surface) was significantly different between groups (ruptured, 47.7 +/- 6 N/cm(2); emergent symptomatic, 47.5 +/- 4 N/cm(2); elective repair, 36.9 +/- 2 N/cm(2); P =.03), with no significant difference in blood pressure (P =.2) or AAA diameter (P =.1). Because of trends toward differences in diameter, comparison was made only with diameter-matched subjects. Even with identical mean diameters, ruptured/symptomatic AAAs had a significantly higher peak wall stress (46.8 +/- 4.5 N/cm(2) versus 38.1 +/- 1.3 N/cm(2); P =.05). Maximal wall stress predicted risk of rupture better than the LaPlace equation (20.7 +/- 5.7 N/cm(2) versus 18.8 +/- 2.9 N/cm(2); P =.2) or other proposed indices of rupture risk. The smallest ruptured AAA was 4.8 cm, but this aneurysm had a stress equivalent to the average electively repaired 6.3-cm AAA. CONCLUSION: Peak wall stresses calculated in vivo for AAAs near the time of rupture were significantly higher than peak stresses for electively repaired AAAs, even when matched for maximal diameter. Calculation of wall stress with computer modeling of three-dimensional AAA geometry appears to assess rupture risk more accurately than AAA diameter or other previously proposed clinical indices. Stress analysis is practical and feasible and may become an important clinical tool for evaluation of AAA rupture risk.