Repair of abdominal aortic aneurysms in high-risk patients

Neural glycomics: the sweet side of nervous system functions

The success of investigations on the structure and function of the genome (genomics) has been paralleled by an equally awesome progress in the analysis of protein structure and function (proteomics). We propose that the investigation of carbohydrate structures that go beyond a cell's metabolism is a rapidly developing frontier in our expanding knowledge on the structure and function of carbohydrates (glycomics). No other functional system appears to be suited as well as the nervous system to study the functions of glycans, which had been originally characterized outside the nervous system. In this review, we describe the multiple studies on the functions of LewisX, the human natural killer cell antigen-1 (HNK-1), as well as oligomannosidic and sialic (neuraminic) acids. We attempt to show the sophistication of these structures in ontogenetic development, synaptic function and plasticity, and recovery from trauma, with a view on neurodegeneration and possibilities to ameliorate deterioration. In view of clinical applications, we emphasize the need for glycomimetic small organic compounds which surpass the usefulness of natural glycans in that they are metabolically more stable, more parsimonious to synthesize or isolate, and more advantageous for therapy, since many of them pass the blood brain barrier and are drug-approved for treatments other than those in the nervous system, thus allowing a more ready access for application in neurological diseases. We describe the isolation of such mimetic compounds using not only Western NIH, but also traditional Chinese medical libraries. With this review, we hope to deepen the interests in this exciting field.

Abdominal aortic aneurysm repair in the veteran population

BACKGROUND

The aim of this study was to audit the outcome of elective open aortic aneurysm repair in a veteran hospital to determine whether age > or =80 years influenced the morbidity or mortality.

METHODS

All elective abdominal aortic aneurysm (AAA) repaired at Greenslopes Private (Repatriation) Hospital between January 1995 and July 2000 were reviewed. Operative details, premorbid condition, postoperative outcomes as well as length of admission were recorded. Patients were grouped according to age as > or =80 years or <80 years.

RESULTS

There were 251 open elective AAA (including infrarenal and suprarenal, as well as recurrent AAA) repairs carried out during this period, 64 of which were patients of age > or =80 years. Cardiovascular risks factors did not differ between groups nor did complication rates for patients > or =80 and <80 years of age (19.1 and 19.8%, respectively). Mortality rates were not significantly different between groups (> or =80 years: 6.25%; <80 years: 4.8%; P > 0.6).

CONCLUSIONS

Age > or =80 years should not be an exclusion criteria when contemplating open elective AAA repair.

Totally laparoscopic abdominal aortic aneurysm repair

Abdominal aortic aneurysm (AAA) resection is a major surgical procedure performed frequently. As a minimal access procedure, laparoscopy has been shown in the field of general surgery to improve a patient's postoperative well-being and to shorten hospital stay. The same benefits could be expected from a laparoscopic approach for AAA repair. We report what we believe to be the first totally laparoscopic AAA repair performed according to the principles of endoaneurysmorrhaphy.

"Pancake kidney": a renal anomaly complicating aortic reconstruction

Pancake kidney is a rare fusion anomaly of the kidneys characterized by the presence of a displaced, lobulated pelvic renal mass of dual parenchymatous system without intervening septum. The existence of this anomaly during aortic reconstruction presents a great technical challenge. The surgical management of a 51-year-old man with a 5.0 cm aortic aneurysm and a pancake kidney is described.

A prospective randomized study comparing exclusion technique and endoaneurysmorrhaphy for treatment of infrarenal aortic aneurysm

PURPOSE

The retroperitoneal approach used in aortic replacement for infrarenal aortic aneurysm has become an important part of the vascular surgeon's armamentarium. Use of the exclusion and bypass technique, however, remains controversial. Although benefits may include reduced blood loss, less operative dissection, and a smoother intraoperative and postoperative course, critics of this technique have alluded to potential drawbacks. In this study the results of the exclusion technique and open endoaneurysmorrhaphy for surgical treatment of abdominal aortic aneurysm were compared.

METHODS

One hundred patients were randomized to either exclusion (EXC) or open endoaneurysmorrhaphy (OP) procedures. A posterolateral left retroperitoneal approach was used in all patients. During surgery, autotransfusion devices were used when needed. Doppler flow and pressures in the excluded aneurysm sac were determined during surgery in EXC to evaluate the completeness of the exclusion.

RESULTS

Patient demographics were similar between the two groups. The mean age was 70 years (range, 53 to 89 years). The operative mortality rates were 0% and 1.9% (1 of 51) in the EXC and OP groups, respectively. Nonfatal postoperative complications occurred in 10.2% (5 of 49) of the EXC group and in 23.5% (12 of 51) of the OP group (p < 0.05). Aneurysm sacs were opened in two EXC procedures. Blood loss (mean +/- SD) was 703 +/- 570 ml in the EXC group and 1031 +/- 703 ml in the OP group (p < or = 0.01). The intensive care unit stay (mean +/- SD) was 1.9 +/- 1.2 days in the EXC group and 3.2 +/- 6.9 days in the OP group (p = NS). The hospital stay (mean +/- SD) was 9.8 +/- 5.8 days and 12.1 +/- 17 days in the EXC and OP groups, respectively (p = NS). There has been persistent flow in the excluded sac in two patients, with sac enlargement in one of these patients on postoperative follow-up by duplex scan or clinical examination.

CONCLUSION

The exclusion and bypass technique for repair of infrarenal aortic aneurysm appeared to be an acceptable technique and was associated with less operative blood loss and fewer postoperative complications than those of open aortic endoaneurysmorrhaphy. Exclusion bypass may contribute to a smoother perioperative course and postoperative treatment of these patients.

Results of 1000 consecutive elective abdominal aortic aneurysm repairs

In order to identify major risks for death and complications from elective repair of abdominal aortic aneurysm, the authors analyzed their experience with the last 1000 such repairs over a 15-year period. Of the patients, 772 were men and 228 were women; average age was 70 (range 37-92) years. Some 20% of the patients had severe chronic obstructive pulmonary disease and 33% had baseline creatinine level > 115 mumol/l. Fifteen patients were dialysis-dependent and 24% (242/1000) had significant cardiac disease. Operation used a retroperitoneal approach in 834 patients and a transperitoneal approach in 166. The perioperative mortality rate was 2.4%, but this did not change either chronologically or with technique: some 50% of the deaths were due to cardiac causes. Renal and pulmonary impairment did not affect mortality or complication; 64% of non-fatal complications were distributed in the renal (17%), pulmonary (19%) and cardiac groups (28%). The authors' experience showed that patients with cardiac disease remain at significant risk for post-abdominal aortic aneurysm repair complications in spite of selective preoperative cardiac evaluation. Renal and pulmonary risk factors did not cause additional mortality or morbidity. They suggest that elective abdominal aortic aneurysm repair can be performed with low mortality and morbidity, even in increasing numbers of high-risk patients.

Aortic replacement for abdominal aortic aneurysm in elderly patients

Improvements in the operative mortality and morbidity rates in elective aortic replacement, which are largely a result of refinements in surgical technique and perioperative management, have allowed a more aggressive approach in the treatment of abdominal aortic aneurysm (AAA) in elderly patients. To evaluate this approach, we reviewed the records of 116 patients 80 years of age and older (range: 80 to 93 years) who consecutively underwent aortic replacement for AAA. Seventy-seven patients underwent elective aortic replacement with 8 complications and a 3% operative mortality rate (2 of 77). Emergent aortic replacement was performed in 39 patients (14 with symptomatic nonruptured AAA and 25 with ruptured AAA) with 12 complications. In this nonselective subset, there were eight deaths, for an operative mortality rate of 20% (symptomatic 14%, ruptured 24%). In comparison, 780 patients less than 80 years of age underwent aortic replacement during the same time period. Within this group, 622 patients who were treated on an elective basis had a similar operative mortality (2%) as did patients 80 years of age and older. On the basis of these results, we believe that elective aortic replacement in elderly patients is justified and can be achieved with low operative mortality and morbidity rates. We suggest that the chronologic age of the patient should not deter aortic replacement.

Late results of small untreated abdominal aortic aneurysms

We report our experience with 73 patients who were initially selected for nonoperative management of an abdominal aortic aneurysm less than 5 cm in diameter. Size of the aneurysm was determined by ultrasound (34); arteriography (16); computerized tomography (17); plain x-ray (4); and magnetic resonance imaging (2). End points of the study were subsequent elective resection, rupture, death from cause other than rupture, or an intact aneurysm followed for a minimum of three years. Overall, 28 (38%) aneurysms were subsequently resected on an elective basis; four (5%) ruptured; 15 (21%) were intact at the time of the patient's death; and 26 (36%) remained intact during follow-up of 3 to 6.5 years. Indications for elective resection were aneurysm enlargement (21); symptoms suggesting impending rupture (3); and improvement in medical condition (4). In the 43 aneurysms initially less than 4 cm diameter, 16 (37%) had elective resection and one (2%) ruptured, and in the 30 that were 4-4.9 cm, 12 (40%) were resected and three (10%) ruptured. The four aneurysms that ruptured had enlarged to greater than 5 cm prior to rupture. We conclude that aneurysms less than 4 cm can be safely followed. Aneurysms 4-4.9 cm should be considered for operation, depending upon the size of the aneurysm, patient's life expectancy, and risk factors for surgery. Any aneurysm that enlarges should be resected, especially if the aneurysm becomes larger than 5 cm in diameter.