Retroperitoneal approach to abdominal aortic aneurysm repair preserves splanchnic perfusion as measured by gastric tonometry.

BACKGROUND: We investigated if minimizing bowel manipulation and mesenteric traction using the retroperitoneal approach in open abdominal aortic aneurysm (AAA) repair preserves splanchnic perfusion, as measured by gastric tonometry, and reduces the systemic inflammatory response and dysfunction of the various organs. METHODS: Patients undergoing elective AAA repair were randomized into three groups. Group I had repair via the retroperitoneal approach, while groups II and III were repaired via the transperitoneal approach with the bowel packed within the peritoneal cavity or exteriorized in a bowel bag, respectively. A tonometer was used to measure gastric intramucosal pH (pHi), as an indicator of splanchnic perfusion, just prior to aortic clamping, during clamping, and at 0.5, 1, 2, 4, 6, and 12 hr after clamp release. Multiorgan dysfunction syndrome (MODS) and systemic inflammatory response syndrome (SIRS) scores were calculated and systemic interleukins (IL-6 and IL-10) measured at predetermined intervals. RESULTS: Thirty-four patients were successfully randomized. The gastric pHi was significantly lower in group II (n=12) and group III (n=11) compared to group I (n=11) during aortic clamping and immediately after clamp release (p<0.05). The aortic clamp time, blood loss, MODS and SIRS scores, and systemic cytokine response were similar in all three groups. When the three groups were combined, there were significant positive correlations between the operation time, aortic clamp time, and amount of blood lost and transfused with plasma IL-6 levels and MODS score on the first postoperative day. CONCLUSION: The retroperitoneal approach for open AAA repair is associated with gastric tonometric evidence of better splanchnic perfusion compared to the transperitoneal approach.

Role of the Hardman index in predicting mortality for open and endovascular repair of ruptured abdominal aortic aneurysm.

PURPOSE: To correlate the Hardman prognostic index with perioperative mortality in patients undergoing open and endovascular repair of ruptured abdominal aortic aneurysm (rAAA). METHODS: Over a 5-year period, 126 patients (109 men; mean age 74 years, range 51-91) underwent open (n=74) or endovascular (n=52) repair of rAAA in a single unit. Five Hardman factors (age>76 years, history of loss of consciousness, ECG evidence of ischemia, hemoglobin<9.0 g/dL, and serum creatinine>0.19 mmol/L) were assessed, and their association with in-hospital or 30-day mortality was evaluated retrospectively by chi-square or logistic regression analysis. RESULTS: The mortality for open repair was 51.4% (38/74) in comparison to 32.7% (17/52) for the endovascular group (p=0.05). On multivariate analysis, loss of consciousness (p=0.03, OR 2.9, 95% CI 1.1 to 7.5) was the only significant predictor of mortality in both groups. The mortality rates for open repair patients with Hardman scores<2 were 43.5% (20/46) in comparison to 22.9% (8/35) for the endovascular group (p=0.06), whereas mortality rates for patients with scores>or=2 were 64.3% (18/28) and 52.9% (9/17) for the respective groups (p=0.54). CONCLUSION: The Hardman index correlates well with mortality in both the open and endovascular groups. Those with a score<2 have a trend toward better survival following endovascular repair compared to open repair, while this benefit is not obvious in patients with a score>or=2.

N-acetylcysteine does not improve the endothelial and smooth muscle function in the human saphenous vein.

Oxidative stress can lead to vein graft dysfunction in the saphenous vein. This ex vivo study is aimed to compare the effects of increasing concentrations of the antioxidant N-acetylcysteine (NAC) with heparinized saline (HS) on endothelial and smooth muscle function in the human saphenous vein. Long saphenous vein segment obtained during infrainguinal bypass surgery was divided into 7 rings; 1 immersed in HS and the remaining 6 in increasing NAC concentrations (0.0025%, 0.005%, 0.01%, 0.02%, 0.03%, and 0.04%). Rings were mounted in an organ bath, and relaxant responses to acetylcholine and sodium nitroprusside were assessed through isometric tension studies. Endothelium-dependent relaxations were observed in 77 vein segments from 11 patients. No significant difference was seen in veins treated with either lower NAC concentrations (0.0025%, 0.005%, 0.01%, 0.02%, and 0.03%) or HS. However, HS-treated veins showed significantly better relaxation compared to those treated with maximum (0.04%) NAC (P < .05). Endothelium-independent relaxations were observed in 91 segments from 13 patients. No difference in relaxation was observed between veins treated with HS or any of the NAC concentrations. In conclusion, lower NAC concentrations do not offer better endothelial protection than HS, whereas the highest NAC concentration has a detrimental effect on endothelium-dependent relaxation. Moreover, NAC did not show beneficial effect on direct smooth muscle relaxation.

Endoleak and endotension following open abdominal aortic aneurysm repair: a report of two cases.

Anastomotic leaks and perigraft seroma are uncommon complications following open repair of abdominal aortic aneurysms; in particular, it is rare for them to cause recurrence and expansion of the aneurysm sac. We report a case of anastomotic leak presenting as type 1 endoleak and another of perigraft seroma causing recurrent pressurization, endotension, and expansion of the original aneurysm sac.

Change in aneurysm diameter after stent-graft repair of ruptured abdominal aortic aneurysms.

PURPOSE: To compare the changes in aneurysm size following endovascular aneurysm repair (EVAR) for ruptured versus elective abdominal aortic aneurysms (AAA). METHODS: Aneurysm sac diameter was measured from computed tomographic (CT) scans in 14 hemodynamically stable patients (14 men; mean age 74+/-7 years, range 60 to 83) prior to emergent stent-graft repair for ruptured AAA. The aneurysm diameter change was followed postprocedurally with serial CT and the outcomes compared to 74 AAA patients (58 men; mean age 74+/-7 years, range 56 to 87) having elective EVAR in the same time period. The mean rate of sac decrease (mm/month) was calculated for each group. RESULTS: There were 3 postoperative deaths in the ruptured AAA cohort, leaving 11 patients available for follow-up analysis (mean 16 months, range 2-49). Eight (73%) patients with ruptured AAA demonstrated significantly decreased (>5 mm) aneurysm diameters compared with 32 (43%) elective cases (p=0.07) followed a mean 20 months (range 3-51). The mean rate of sac diameter decrease was 1.50+/-1.03 mm/month in the rupture group versus 0.73+/-0.86 mm/month in the elective group (p=0.04). CONCLUSIONS: This study suggests that ruptured AAAs treated with stent-graft experience sac regression at a higher rate compared with electively treated AAA. The reasons for these findings remain unclear.

Synergism between radiotherapy and vascular risk factors in the accelerated development of atherosclerosis: a report of three cases.

Radiotherapy is commonly used in the management of testicular tumors. However, to date the risk of radiation-induced vascular occlusive disease in men following radiotherapy for testicular cancer has not been regarded as a major factor in their long-term care. Several animal studies have shown the importance of established vascular risk factors such as hypercholesterolemia and hypertension in the pathogenesis of radiation-induced atherosclerosis. This report presents three cases of premature chronic iliofemoral arterial disease presenting 5,13, and 16 years following exposure to therapeutic irradiation for the treatment of testicular cancer. The patients were in the age group of 40-45 years and all demonstrated associated known atherosclerotic risk factors. The patients had received radiotherapy in the dose of 3,500-4,000 rads in a standard "dog-leg" fashion to the ipsilateral aortoiliac lymphatic chain. Our results showed that young men treated with radiotherapy for testicular cancer may be targeted from the outset for atherosclerotic risk factor reduction to minimize the risk of development of late chronic occlusive arterial disease. It may be that a cohort of men so treated with historical regimes of radiotherapy and now entering middle age should be screened for arterial disease and risk factor reduction.