Natural history of descending thoracic and thoracoabdominal aortic aneurysms

ObjectivesElucidating critical aortic diameters at which natural complications (rupture, dissection, and death) occur is of paramount importance to guide timely surgical intervention. Natural history knowledge for descending thoracic and thoracoabdominal aortic aneurysms is sparse. Our small early studies recommended repairing descending thoracic and thoracoabdominal aortic aneurysms before a critical diameter of 7.0 cm. We focus exclusively on a large number of descending thoracic and thoracoabdominal aortic aneurysms followed over time, enabling a more detailed analysis with greater granularity across aortic sizes.MethodsAortic diameters and long-term complications of 907 patients with descending thoracic and thoracoabdominal aortic aneurysms were reviewed. Growth rates (instrumental variables approach), yearly complication rates, 5-year event-free survival (Kaplan–Meier), and risk of complications as a function of aortic height index (aortic diameter [centimeters]/height [meters]) (competing-risks regression) were calculated.ResultsEstimated mean growth rate of descending thoracic and thoracoabdominal aortic aneurysms was 0.19 cm/year, increasing with increasing aortic size. Median size at acute type B dissection was 4.1 cm. Some 80% of dissections occurred below 5 cm, whereas 93% of ruptures occurred above 5 cm. Descending thoracic and thoracoabdominal aortic aneurysm diameter 6 cm or greater was associated with a 19% yearly rate of rupture, dissection, or death. Five-year complication-free survival progressively decreased with increasing aortic height index. Hazard of complications showed a 6-fold increase at an aortic height index of 4.2 or greater compared with an aortic height index of 3.0 to 3.5 (P < .05). The probability of fatal complications (aortic rupture or death) increased sharply at 2 hinge points: 6.0 and 6.5 cm.ConclusionsAcute type B dissections occur frequently at small aortic sizes; thus, prophylactic size-based surgery may not afford a means for dissection protection. However, fatal complications increase dramatically at 6.0 cm, suggesting that preemptive intervention before that criterion can save lives.     

Emergency surgery for thoracoabdominal aortic aneurysms with acute presentation

PURPOSE: The mortality rate for elective repair of thoracoabdominal aortic aneurysms is as low as 4% in some surgical centers. However, patients with emergent presentation with acute pain, rupture, or complicated acute dissection traditionally have a poor outcome. We evaluated the results of surgery in a large contemporary series of patients with acute presentation at a tertiary referral center with a special interest and experience in aortic surgery. METHODS: Between 1986 and 1998, 1220 patients underwent repair of thoracoabdominal aortic aneurysms. One hundred twelve patients had acute presentation, and 1108 patients underwent elective repair. Data were collected in a prospectively generated database. RESULTS: Seventy-six patients had rupture, and 36 patients had acute dissection without rupture. The operative mortality rate was 6% for elective cases and 17% for acute cases (P =.0004). The long-term survival was longer for the elective group compared with the acute group (mean, 8.3 +/- 0.4 years versus 5.5 +/- 0.7 years; P <.005). Age did not influence survival rate in the acute group. Postoperative pulmonary complications, paraplegia/paraparesis, and renal impairment occurred in 45%, 14%, and 25%, respectively, of acute cases and were significantly more common than in elective cases (P < or =.01). Left heart bypass was used in 34 acute patients (30%), and intercostal arteries were reattached in 66 acute patients (59%). Surgery without the use of either adjunct was associated with significantly higher mortality and renal impairment rates. CONCLUSION: Repair of thoracoabdominal aortic aneurysms with acute presentation is associated with worse outcome compared with elective cases. Nevertheless, repair may be performed with reasonable mortality and morbidity rates at specialized centers. In the acute setting, the use of surgical adjuncts is associated with improved outcome and should be used when possible. Age does not impact on survival rate in patients with acute presentation, and surgery should not be restricted to only younger patients.     

Reproducibility of thoracic aortic diameter measurement using computed tomographic scans.

OBJECTIVES: Decisions to recommend elective surgical repair of thoracic aortic aneurysms (TAA) may be based on size or expansion rate, which are used as indices of the risk of rupture. Measurement error may thus affect clinical decision-making. In order to evaluate the reproducibility of aortic diameter measurements of TAA, we assessed departmental inter- and intra-observer variability of measurement of pre-selected computed tomographic scan images of aneurysmal segments of the thoracic aorta. METHODS: We compared measurements of minimum aortic diameter made by four observers in 50 pre-selected scans and at different times by two observers using a calliper method and a measurement tool within the scan. Differences in measured dimension were analysed using Wilcoxon's signed ranks test and the repeatability assessed using the method of Bland and Altman. RESULTS: There were no significant inter-observer differences among three observers but there were significant differences between another observer and two other observers (P < 0.05). No significant intra-observer differences existed. The best intra-observer repeatability was 2.25 while the worst inter-observer repeatability was 4.37. The mean and maximum difference in measurement were +/-0.88 mm and +/-8.0 mm, respectively. Variability of measurement increased with aortic diameter. CONCLUSIONS: Calliper measurement of TAA is an acceptable measurement method for surveillance of TAA but appears most accurate with a single observer. Increasing error is seen with increasing diameter which may compound error in estimation of expansion rate. Standardisation of technique is advisable for multiple observers and aortic units should adopt quality assurance protocols to minimise error.     

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.)     

A new predictive model for adverse outcomes after elective thoracoabdominal aortic aneurysm repair

BACKGROUND: Recent recommendations have emphasized individualized treatment based on balancing a patient's risk of thoracoabdominal aortic aneurysm rupture with the risk of an adverse outcome after surgical repair. The purpose of this study was to determine which preoperative risk factors currently predict an adverse outcome after elective thoracoabdominal aortic aneurysm repair. METHODS: A single, composite end point termed adverse outcome was defined as the occurrence of any of the following: death within 30 days, death before discharge from the hospital, paraplegia, paraparesis, stroke, or acute renal failure requiring dialysis. A risk factor analysis was performed using data from 1,108 consecutive elective thoracoabdominal aortic aneurysm repairs. RESULTS: The incidence of an adverse outcome was 13.0% (144 of 1,108 patients); predictors included preoperative renal insufficiency (p = 0.0001), increasing age (p = 0.0035), symptomatic aneurysms (p = 0.020), and extent II aneurysms (p = 0.0001). These risk factors were used to construct an equation that estimates the probability of an adverse outcome for an individual patient. CONCLUSIONS: This new predictive model may assist in decisions regarding elective thoracoabdominal aortic aneurysm operations. For patients who are acceptable candidates, contemporary surgical management provides favorable results.     

Management of thoracoabdominal aneurysm type IV.

BACKGROUND: Thoracoabdominal aneurysm type IV (TAA IV) represents only a minority of aortic aneurysms, but as it is an entirely abdominally located aneurysm, vascular surgeons are likely to see such aneurysms in their practice. The current surgical management of TAA IV is reviewed. METHODS: A PubMed/Medline-literature search for TAA IV. RESULTS AND CONCLUSIONS: A detailed preoperative evaluation to determine the rupture and operative risk is required. A threshold size of 5.5-6 cm is recommended for elective repair of TAA IV, which then is adjusted for age and other risk factors. Operative simplicity with the clamp and sew approach to obtain a short aortic cross-clamp time seems to have most support in the literature. The necessity of adjunct treatment to prevent visceral and spinal cord ischemia seems to be needed rarely. Uncomplicated repair has a minimal risk of neurological injury and a low risk of renal failure requiring dialysis in patients without preoperative renal dysfunction or renal artery stenosis. The role of endovascular repair of these aneurysms remains to be established.     

Elective abdominal aortic aneurysm repair: does the aneurysm diameter influence long-term survival?

OBJECTIVES: The aim of this study was to investigate whether initial abdominal aortic aneurysm (AAA) diameter influences long-term survival after elective repair. DESIGN: Retrospective analysis of database. MATERIAL AND METHODS: Between March 1995 and December 2006, a consecutive series of 895 patients underwent elective treatment of an AAA either by open surgical or endovascular repair. An AAA diameter of 5.5cm was chosen as threshold to distinguish between small and large aneurysms, according to the definition given by the UK small aneurysm trial. Patient characteristics and distribution of basic risk factors were assessed. Survival estimates (Kaplan-Meier) and Cox proportional hazards regression results are reported. RESULTS: Patients with small aneurysms were more likely to survive the first 6 years after AAA repair, even after adjustment for treatment modality and baseline risk factors. After adjustment for age and sex aneurysms with smaller diameter were related to a lower risk of death (p<0.0016). CONCLUSIONS: Patients with small aneurysms (< or =5.5cm) have an improved long-term survival than patients with larger aneurysms.     

Offen chirurgische Therapie extensiver thorakaler und thorakoabdominaler Aortenaneurysmata

The continuous development of endovascular techniques for the treatment of diseases of the descending thoracic/thoracoabdominal aorta requires the careful evaluation of the safety and efficacy, especially the reliability of the long-term results in comparison to the established gold standard – open surgical repair of the aorta. The maximum diameter of the thoracic/thoracoabdominal aorta as well as its average progression are deciding parameters in the selection of the treatment. The surgical results after open surgical aortic repair have significantly improved over the past 20 years with various technical improvements, e.g., distal aortic perfusion or selective visceral perfusion, while maintaining very good long-term results. In the meantime, experienced aortic surgical centers regularly achieve substantially lower in-hospital mortality and paraplegia rates than previously reported. In addition, optimized perioperative management contributes substantially to the very good long-term prognosis of patients with thoracic and thoracoabdominal aortic aneurysms (TAA/A) undergoing open surgery. The following contribution presents the Leipzig strategy for conventional, open surgical TAA/A treatment.     

Management of isolated common iliac artery aneurysms

Purpose: Since isolated common iliac artery aneurysms are rare and there is no consensus regarding some aspects of their management, we reviewed our recorded experience with common iliac artery aneurysms from 1977 through 1993. Methods: We were able to identify 25 patients having a total of 33 common iliac artery aneurysms on the basis of information maintained by our medical records staff, old surgical logs and a departmental registry that was implemented in 1989. Follow-up data were collected from outpatient charts and by telephone contact. New imaging studies were obtained for 14 patients who either underwent common iliac artery aneurysm repair without aortic replacement (aortic ultrasound scans, n = 7) or had no surgical treatment whatsoever (computerized tomography of the abdomen and pelvis, n = 7). Results: All 25 patients were men (mean age, 71 years). Eighteen patients (72%) had elective (n = 14) or urgent (n = 4) operations to repair common iliac artery aneurysms with mean diameters of 3.8 cm and 5.8 cm, respectively. There was one postoperative death (5.5%) in conjunction with complementary renal revascularization in a patient with preoperative renal insufficiency. During a mean follow-up period of 50 months, two (29%) of the seven patients who had not received bifurcation grafts at the time of their common iliac artery aneurysm procedures had developed infrarenal aortic aneurysms. Seven (28%) of the original 25 patients were observed without intervention for common iliac artery aneurysms measuring 2–2.5 cm in diameter. No common iliac artery aneurysm enlargement or new aortic aneurysms have been documented in any of these patients at a mean follow-up interval of 57 months. Conclusions: In our limited experience, the risk for spontaneous rupture appears to be concentrated among common iliac artery aneurysms exceeding 5 cm in diameter, while those that are less than 3 cm in diameter may fail even to enlarge under observation. Therefore, common iliac artery aneurysms measuring ≥3 cm in size probably warrant surgical treatment, at which time simultaneous aortic replacement also should be a serious consideration.     

Aortic aneurysm in heart transplant recipients

Purpose: The purpose of this study was to define the clinical features of aortic aneurysms occurring in heart transplant recipients.Methods: Among the 734 patients who have undergone heart transplantation at our institution over the last 14 years, we have identified 12 patients (1.6% incidence) with aortic aneurysms (9 infrarenal, 3 thoracoabdominal), making this the largest reported series of aortic aneurysms (AA) in heart transplant recipients.Results: For nine of the 12 patients with AA (75%), the indication for transplantation was ischemic cardiomyopathy. This indication accounted for only 42% of the overall transplantation group; our data therefore show that the risk of infrarenal AA disease was higher for patients who underwent transplantation for ischemic cardiomyopathy than for other indications ( p = 0.02). In two of the patients with thoracoabdominal AA, chronic dissection was identified as the specific AA cause, whereas all of the other patients in the study had nonspecific "atherosclerotic" AAs. All 12 patients were symptom free at the time of initial discovery of the AAs. Two of the patients with infrarenal AA were diagnosed with AAs before transplantation; for the seven remaining patients with infrarenal AAs, the mean time between transplantation and AA discovery was 5.0 years (range 1.2 to 11.8 years). Serial radiologic studies allowed us to determine the AA expansion rate in seven of the 12 patients. This rate varied from 0 to 2.53 cm/yr (mean 1.20 cm/yr; 1.0 cm/yr for infrarenal AA alone). Five patients with infrarenal AA underwent AA repair as the initial treatment. Three others underwent repair after their AAs significantly expanded under observation. Mean AA diameter at the time of repair was 6.9 cm. All three patients with thoracoabdominal AAs died of acute AA rupture before resection could be done, despite their initial asymptomatic state. AA diameters at time of rupture were 3.5, 6.0, and 11 cm. All of the eight patients with AA treated with surgery are alive and well (median follow-up 18 months). The only complication was acute heart transplant rejection, which occurred 11 days after AA repair in one patient.Conclusions: Our data suggest that AA occurrence is more likely in patients who undergo heart transplantation for ischemic heart disease than for other indications. Careful serial radiologic surveillance is warranted in any heart transplant patient with an AA, because of the apparent potential for more rapid AA expansion in this patient population than in patients who do not undergo transplantation. We conclude that early repair of infrarenal AA is indicated because excellent operative results and low morbidity rates can be achieved. An aggressive approach to thoracoabdominal AAs in this group may also be appropriate because of the apparent propensity to lethal rupture, sometimes at relatively small AA size. (J VASC SURG 1995;22:689-96.)     

Risk factors for rupture of chronic type B dissections

OBJECTIVE:This study was an attempt to determine risk factors for rupture and to improve management of patients with type B aortic dissection who survive the acute phase without operation. METHODS: We studied 50 patients by means of serial computer-generated 3-dimensional computed tomographic scans. All patients who did not undergo operative treatment before the completion of at least 2 computed tomographic scans a minimum of 3 months apart after an acute type B dissection were included in the study. The median duration of follow-up was 40 months (range 0.9-112 months). Only 1 patient died of causes unrelated to the aneurysm during follow-up. Nine patients had fatal rupture (18%); 10 patients underwent elective aneurysm resection because of rapid expansion or development of symptoms, and 31 patients remained alive without operation or rupture. Possible risk factors for rupture in patients in the rupture, operative, and event-free groups were compared, as were dimensional data from first follow-up and last computed tomographic scans. RESULTS: Older age, chronic obstructive pulmonary disease, and elevated mean blood pressures were unequivocally associated with rupture (rupture versus event-free survival, P <.05), and pain was marginally significantly associated. Analysis of dimensional factors contributing to rupture was complicated by the fact that patients who underwent elective operation had significantly larger aneurysms and faster expansion rates than did either of the other groups, leaving comparisons of aneurysmal diameter between groups with and without rupture showing only marginal statistical significance. The last median descending aortic diameter before rupture in the rupture group was 5.4 cm (range 3.2-6. 7 cm). CONCLUSIONS: In an environment in which patients with large and rapidly expanding aneurysms are usually referred for surgical treatment, older patients with chronic type B dissections, especially if they have uncontrolled hypertension and a history of chronic obstructive pulmonary disease, are significantly more likely to have rupture than are younger, normotensive patients without lung disease. Neither the presence of a persistently patent false lumen nor a large abdominal aortic diameter appears to increase the risk of rupture. Overall, our nondimensional data strikingly resemble the natural history of patients with nondissecting aneurysms, suggesting that calculations derived from data on chronic descending thoracic and thoracoabdominal aneurysms would provide an overly conservative individual estimate of rupture risk for patients with chronic type B dissection, who tend toward earlier rupture of smaller aneurysms. A more aggressive surgical approach toward treatment of patients with chronic type B dissection seems warranted.     

Thirty-day mortality statistics underestimate the risk of repair of thoracoabdominal aortic aneurysms: a statewide experience

OBJECTIVE: The purpose of this study was to determine the 30-day and 365-day mortality for the repair of thoracoabdominal aortic aneurysms (TAA), when stratified by age, in the general population. These data provide clinicians with information more applicable to an individual patient than mortality figures from a single institutional series. METHODS: Data were obtained from the California Office of Statewide Health Planning and Development (OSHPD) for the years 1991 to 2002. These data were linked to the state death certificate file, allowing for continued information on the status of the patients after hospital discharge. All patients undergoing elective and ruptured TAA repair as coded by International Classification of Diseases, 9th Clinical Modification (ICD-9, CM) in California were identified. Patients aged <50 or >90 years old were excluded. We determined 30- and 365-day mortality and stratified our findings by decade of patient age (eg, 50 to 59). Demographics of elective and ruptured cases were also compared. RESULTS: We identified 1010 patients (797 elective, 213 ruptured) who underwent TAA repair. Mean patient ages were 70.0 (elective) and 72.1 years (ruptured). Men comprised 62% of elective and 68% of ruptured aneurysm patients, and 80% (elective) and 74% (ruptured) were white. Overall elective patient mortality was 19% at 30 days and 31% at 365 days. There was a steep increase in mortality with increasing age, such that elective 365-day mortality increased from about 18% for patients 50 to 59 years old to 40% for patients 80 to 89 years old. The elective case 31-day to 365-day mortality ranged from 7.8% for the youngest patients to 13.5%. Mortality for ruptured cases was 48.4% at 30 days and 61.5% at 365 days, and these rates also increased with age. CONCLUSIONS: Our observed 30-day mortality for TAA repairs is consistent with previous reports; however, mortality at 1 year demonstrates a significant risk beyond the initial perioperative period, and this risk increases with age. These data reflect surgical mortality for TAA repair in the general population and may provide more useful data for surgeons and patients contemplating TAA surgery.     

Descending Thoracic and Thoracoabdominal Aortic Aneurysm Repair: 15-Year Results Using a Uniform Approach

This review presents the results of surgical repair of descending thoracic (DT) and thoracoabdominal aortic (TAA) aneurysms, using spinal drainage (SD) distal aortic perfusion (DAP), and other adjuncts intended to reduce complications. Records of patients undergoing repair of DT and TAA between 1986 and 2002 were reviewed. Elective operations were performed using single lung ventilation, invasive monitoring, SD, modest anticoagulation, permissive hypothermia (33°F), liberal use of transaortic endarterectomy, and complete repair. Intercostal arteries were reimplanted when possible and DAP was used in DT and TAA types I, II, and III repair. Exceptions to this approach were noted. Some of these adjuncts were used in emergency cases. Actuarial survival was calculated. Fifty consecutive patients with DT (3) or TAA (47), type I (4), type II (16), type III (18), or type IV (9), aneurysms received elective (36) or emergency (14) repair between 1986 and 2002. Mortality was 2/36 (5.5%) in the elective group. In the emergency group, there were 2 intraoperative deaths and mortality was 4/14 (28.5%, p < 0.07). Overall survivor morbidity was 6/34 (17.6%) in elective and 7/10 (70%, p < 0.02) in emergency cases. Paraplegia occurred in one patient in the elective group (2.7%) with dissecting type II TAA aneurysm in whom the intercostal patch was sacrificed. Two of 12 initial survivors developed paraplegia in the emergency group (16.7%); one had SD but neither had DAP or intercostal reimplantation. Serious complications were associated with avoidable deviations from the approach. Five and 10-year survival for the entire series was 64.8% and 46.4%, respectively. These results parallel those in contemporary reports from centers where repair of descending and thoracoabdominal aortic aneurysm is frequently performed. Good long-term results can be achieved using spinal drainage and distal aortic perfusion, combined with other adjuncts as a means of reducing complications. When possible, the same approach should be used in emergency cases.Presented at the 17th Annual Meeting of the Western Vascular Society, Newport Beach, CA, September 22-25, 2002.     

Abdominal aortic aneurysm rupture rates: A 7-year follow-up of the entire abdominal aortic aneurysm population detected by screening

Purpose: The goal of the current study was to identify the risk of rupture in the entire abdominal aortic aneurysm (AAA) population detected through screening and to review strategies for surgical intervention in light of this information. Methods: Two hundred eighteen AAAs were detected through ultrasound screening of a family practice population of 5394 men and women aged 65 to 80 years. Subjects with an AAA of less than 6.0 cm in diameter were followed prospectively with the use of ultrasound, according to our protocol, for 7 years. Patients were offered surgery if symptomatic, if the aneurysm expanded more than 1.0 cm per year, or if aortic diameter reached 6.0 cm. Results: The maximum potential rupture rate (actual rupture rate plus elective surgery rate) for small AAAs (3.0 to 4.4 cm) was 2.1% per year, which is less than most reported operative mortality rates. The equivalent rate for aneurysms of 4.5 to 5.9 cm was 10.2% per year. The actual rupture rate for aneurysms up to 5.9 cm using our criteria for surgery was 0.8% per year Conclusion: In centers with an operative mortality rate of greater than 2%, (1) surgical intervention is not indicated for asymptomatic AAAs of less than 4.5 cm in diameter, and (2) elective surgery should be considered only for patients with aneurysms between 4.5 and 6 cm in diameter that are expanding by more than 1 cm per year or for patients in whom symptoms develop. In centers with elective mortality rates of greater than 10% for abdominal aortic aneurysm (AAA) repair, the benefit to the patient of any surgical intervention for an asymptomatic AAA of less than 6.0 cm in diameter is questionable. (J Vasc Surg 1998;28:124-8.)     

Aneurysmen der thorakalen und thorakoabdominalen Aorta

The incidence and operations of thoracic and thoracoabdominal aortic aneurysms have significantly increased. The indications for repair are considered to be a diameter of 6 cm or more and 5.5 cm for patient groups with increased risk of rupture. Complex open surgical repair is associated with significant mortality and complication rates. Total or hybrid endovascular repair seems to reduce early postoperative complications and mortality. The endovascular approach has evolved to be a good and predominant alternative to open repair of these aneurysms for older and high-risk patients as well as for aneurysms with optimal morphological suitability. Notwithstanding, at present a complete paradigm shift from open to endovascular repair for all patients, especially those with complex aneurysms, cannot yet be established.     

A registry-based rationale for discrete intervention thresholds for open and endovascular elective abdominal aortic aneurysm repair in female patients

Objective

An evidence-based consensus for a female-specific intervention threshold for abdominal aortic aneurysms (AAAs) is missing. This study aims to analyze sex-related differences in the epidemiology of ruptured AAA to establish an intervention threshold for women.

Ruptured descending and thoracoabdominal aortic aneurysms

BACKGROUND: Advances in end-organ protection have dramatically reduced the incidence of the life-threatening complications associated with the elective repair of thoracoabdominal and descending thoracic aortic aneurysms. However, in the setting of a ruptured thoracic aneurysm, one may not have the luxury of complex end-organ support. We analyzed our experience with ruptured thoracic aneurysms to define morbidity and mortality in the present era. METHODS: One hundred seventy-two patients with thoracoabdominal or descending thoracic aneurysms were operated on between July 1997 and October 2001. Forty presented with either a contained or free rupture. Three techniques were used for aortic reconstruction: clamp and sew, left heart bypass, and hypothermic circulatory arrest. Adjuncts for neurologic and renal support were used when circumstances and anatomy permitted. RESULTS: Seven of 40 patients died in the hospital (17.5%). Four patients died intraoperatively, all of acute myocardial infarction. Five of the seven deaths were in patients who presented in shock. Two patients (5%) experienced paraplegia, 3 (7.5%) had renal failure requiring hemodialysis, 8 (20%) required a tracheostomy, and 6 (15%) had recurrent nerve palsies. There was one stroke (2.6%). Mean diameter of ruptured aneurysms was 8.5 cm. CONCLUSIONS: Ruptured thoracic aneurysms can be repaired with a gratifying rate of salvage. Rapid diagnosis and triage for repair is necessary to avoid progressive deterioration into shock. The incidence of myocardial infarction, and the mortality associated with this event, underscores the need for aggressive cardiac evaluation in the elective thoracic aneurysm patient. The size at rupture also emphasizes the need for earlier referral for elective aneurysm repair.     

Endovascular abdominal aortic aneurysm repair

Around two-thirds of abdominal aortic aneurysms (AAA) are incidentaldiscoveries during the investigation of backache, hip pain orurinary tract complaints. They are much more common in men thanwomen (5:1) and account for 2% of all deaths in men aged >60yr. Open surgical repair of the aneurysm is considered as thestandard, traditional method of treatment. Surgery is recommendedwhen the AAA exceeds 55 mm in anteroposterior diameter as measuredby ultrasound scan. The risk of spontaneous rupture dependson aneurysm size, ranging from <1% per annum for AAA <55mm diameter to >17% per annum for aneurysms >60 mm diameter.Ninety per cent of AAAs are located distal to the renal arteries. Endovascular repair of an aortic aneurysm using an in-situ prostheticgraft was suggested as a technique in 1969 by Dotter, but wasonly first performed successfully by Parodi and colleagues in1990. Over the last 10 yr, the availability of endovascularstent grafts has provided an alternative treatment for patientswith AAA, especially the elderly with significant co-existingmedical conditions. Endovascular repair is much less invasive.However, it is challenging technically and requires a multidisciplinaryapproach. During endovascular surgery, an aortic stent graft is passedvia the femoral arteries through the aortic lumen to fit tightlyabove and below the AAA. The aim is to exclude the aneurysmsac from the systemic circulation, thereby decreasing or eliminatingthe risk of future rupture. The procedure is performed throughincisions in one or both groins; no laparotomy is required.However, certain anatomical considerations apply.     

Surgical repair of aneurysms involving the suprarenal, visceral, and lower thoracic aortic segments: early results and late outcome

OBJECTIVE: The purpose of this study is to review our experience with surgical repair of lower thoracoabdominal and suprarenal aortic aneurysms to determine early and late survival rates and identify factors influencing morbidity and survival among these patients. MATERIALS: From 1989 through 1998, 165 consecutive patients underwent repair of 108 thoracoabdominal (55 group III and 53 group IV) and 57 suprarenal aneurysms. The study group consisted of 109 men and 56 women with a mean age of 70 years (median, 70 years; range, 29-89 years). Mean aneurysm diameter was 6.9 cm (median, 6.5 cm; range, 4-12 cm). There were 125 aneurysms (76%) repaired electively; 40 repairs (24%) were nonelective. The cause of 12 aneurysms (7%) was chronic aortic dissection; the remaining 153 (93%) were degenerative aneurysms. RESULTS: The early postoperative (30-day) mortality rates were 7% (9/125) for elective and 23% (9/40) for nonelective operations (P =.016). For both elective and urgent procedures, early mortality was 1.8% (1/57) for suprarenal aneurysm repair, 11% (6/53) for group IV thoracoabdominal aneurysms, and 20% (11/55) for group III thoracoabdominal aneurysms (P =.013, suprarenal vs group III). Spinal cord ischemia occurred after 6% (10/165) of aneurysm repairs (4% paraplegia, 2% paraparesis). None of the 57 suprarenal aneurysm repairs were complicated by spinal cord ischemia, whereas it occurred in 2% (1/53) of group IV thoracoabdominal aneurysms and 16% (9/55) of group III thoracoabdominal aneurysms (P =.001, suprarenal vs group III; P =. 016, group IV vs group III). Three (25%) of the 12 patients with dissection developed spinal cord ischemia; this compared with seven (5%) of 153 patients with degenerative aneurysms (P =.027). The cumulative 3-year survival rate for the entire series was 71% (95% CI, 64%-79%), and 5-year survival was 50% (95% CI, 40%-60%). CONCLUSIONS: Aneurysms involving the suprarenal, visceral, and lower thoracic aorta may be repaired with acceptable perioperative mortality and late survival rates. The risk of spinal cord ischemia is increased for patients with aortic dissection and may be stratified according to the proximal extent of the aneurysm.     

Hybrid-procedures for the treatment of thoracoabdominal aortic aneurysms and dissections.

AIM: The conventional open repair of thoracoabdominal aneurysms and dissections remains complex and demanding and is associated with significant morbidity and mortality. We present our experience of hybrid open and endovascular treatment of thoracoabdominal aneurysms and dissections. METHODS: Within an experience of 226 aortic stent-grafts between 1998 and April 2006, 6 of the patients (median age 60 years, range 35 to 68 years) with thoracoabdominal aneurysms (Crawford type I, II, III, and V) were treated with a combined endovascular and open surgical approach. Five men and one woman, with median aneurysm diameter of 75 mm (range 70-100 mm), received revascularization of the renal arteries, the superior mesenteric artery, and the coeliac trunk accomplished via transperitoneal bypass grafting. Aneurysmal exclusion was then performed by stent-graft deployment. RESULTS: The entire procedure was technically successful in all patients. The patients were discharged a median of 9 days after the operation, while the postoperative studies revealed the patency of the vessels and no evidence of type I endoleak or secondary rupture of the aneurysm. During follow up (1 to 22 months) spiral-CT scanning revealed distinct shrinkage of the aneurysm, no graft migration or endoleak and patency of all revascularised vessels, except one renal artery in two patients. No patient experienced any temporary or permanent neurological deficit, and no dialysis was necessary. CONCLUSION: The combined endovascular and open surgical approach is feasible, without cross clamping of the aorta and with minimized ischemia time for renal and visceral arteries, and seems to be an appropriate strategy for patients with a thoraco-abdominal aortic aneurysm or dissection.