Athanassios I. Tsoukas

Popliteal-to-distal bypass grafts for limb salvage in diabetics

Between January 1984 and August 1989, 117 diabetic patients with a palpable popliteal pulse but distal limb threatening ischaemia underwent 124 popliteal artery (or below) to distal bypass grafts. All grafts were intra-operatively monitored. The operative mortality was 0.8% and the 30 day primary patency 93%. Primary patencies at 1 and 3 years were 88.6 and 85.2%, respectively. The results of using the popliteal artery as the proximal graft inflow site in diabetes are comparable to other patient groups and to alternative more proximal inflow sites, but require a shorter length of vein graft with a shorter vein harvesting incision, avoid groin disection and result in a more peripheral operation.

Endovascular repair of infrarenal aortic aneurysms in octogenarians and nonagenarians

OBJECTIVE The purpose of this report was to present short and midterm results of endovascular aortic aneurysm repair (EVAR) of infrarenal aortic aneurysms in octogenarians and nonagenarians. METHODS Between March 1994 and March 2011, elective EVAR was performed in 967 patients in our institution. This includes 279 patients older than 80 years at the time of the procedure (octogenarians: n = 252, nonagenarians: n = 27). Mean follow-up was 48.4 ± 34.5 months. A retrospective analysis was performed. Survival was calculated using Kaplan-Meier analysis and a survival comparison to patients who underwent EVAR <80 years old (n = 688) was performed. Cox hazard regression analysis was used to assess parameters that influence survival. RESULTS Technical success was 96% in octogenarians and 85% in nonagenarians. Technical failure in 15 of 279 patients includes primary type I endoleak (n = 6), procedure abortion due to inability to pass the iliac vessels (n = 6), and emergency conversion (n = 3). Thirty-day mortality was significantly higher for patients >80 years old (2.8% vs 1.0%; P = .044). Morbidity rates were 11.5% for octogenarians and 7.4% for nonagenarians with predominately cardiopulmonary complications. High-risk patients >80 years old showed a comparable perioperative mortality rate to low-/medium-risk patients >80 years old (2.9% vs 2.5%;P = .717), but a significantly higher complication rate (22.5% vs 9.2%; P = .0275) and reduced midterm survival with 1-, 3-, and 5-year survival rates of 79% ± SE 7%, 55% ± SE 8%, and 38% ± SE 9% (log-rank test P = .03). In high-risk patients age >80 years old, their age did not influence 30-day mortality (2.5% vs 2.7%; P = .978) and midterm survival. Survival in octogenarians at 1, 3, and 5 years was 87.9 ± SE 2.1%, 70.9 ± SE 3.0%, and 55.6% ± SE 3.5%, respectively. Survival in nonagenarians at 1 and 3 years was 96.3% ± SE 4% and 60.6% ± SE 10.4%. Higher cardiac (hazard ratio [HR], 1.22; P = .038) and renal risk scores (HR, 1.59; P = .0016), chronic obstructive pulmonary disease (HR, 1.56; P = .032), and anemia (HR, 2.1; P < .001) influenced midterm survival. CONCLUSION EVAR in octogenarians and nonagenarians is associated with a significantly higher but still low perioperative mortality compared to younger patients. Midterm survival in octogenarians and nonagenarians, although significantly lower than in younger patients, is still acceptable, indicating that age >80 years should not be an exclusion criteria for EVAR. Even high-risk patients >80 years can be treated safely with a low perioperative mortality and comparable midterm outcome to younger high-risk patients.

Clinical experience with the use of bivalirudin in a large population undergoing endovascular abdominal aortic aneurysm repair

PURPOSE To retrospectively evaluate the safety and effectiveness of the use of bivalirudin, a direct thrombin antagonist, compared with unfractionated heparin in endovascular aneurysm repair (EVAR). MATERIALS AND METHODS Between March 1994 and September 2007, 740 consecutive patients (mean age, 75.7 y +/- 7.7; 69 women) underwent elective EVAR for infrarenal abdominal aortic aneurysm. Bivalirudin was used in 98 of these 740 (13.2%) and unfractioned heparin was used in the other 642 (86.8%). Complications were classified according to the Society of Vascular Surgery/International Society for Cardiovascular Surgery criteria. Major bleeding was defined as clinically overt blood loss resulting in a decrease of hemoglobin of more than 3 g/dL, any decrease in hemoglobin of more than 4 g/dL, transfusion of 2 U or more of red blood cells, or intracranial or retroperitoneal hemorrhage. RESULTS Grade 1 major complications were observed in 161 of 642 patients (25.2%) in the heparin group and 12 of 98 patients (12.2%) in the bivalirudin group (P = .0046), whereas the incidences of grade 3 major complications were not significantly different between groups (P = .57). The rate of total complications was higher in the heparin group than in the bivalirudin group (247 of 642 [38.5%] vs 21 of 98 [21.4%]; P = .001). Major bleeding occurred in 10 of 98 patients (10.2%) receiving bivalirudin and in 91 of 642 patients (14.2%) receiving heparin (P = .34). One of 21 major complications (4.76%) in the bivalirudin group and 12 of 247 major complications (4.86%) in the heparin group were attributable to thrombosis (P = 1.0). CONCLUSIONS Bivalirudin is a safe and feasible alternative to unfractionated heparin in patients undergoing EVAR.

Adequacy of an early arterial phase low-volume contrast protocol in 64-detector computed tomography angiography for aortoiliac aneurysms

PURPOSE This retrospective study was conducted to determine whether a low-volume contrast medium protocol provides sufficient enhancement for 64-detector computed tomography angiography (CTA) in patients with aortoiliac aneurysms. METHODS Evaluated were 45 consecutive patients (6 women; mean age, 72 +/- 6 years) who were referred for aortoiliac computed tomography angiography between October 2005 and January 2007. Group A (22 patients; creatinine clearance, 64.2 +/- 8.1 mL/min) received 50 mL of the contrast agent. Group B (23 patients; creatinine clearance, 89.4 +/- 7.3 mL/min) received 100 mL of the contrast agent. The injection rate was 3.5 mL/s, followed by 30 mL of saline at 3.5 mL/s. Studies were performed on the same 64-detector computed tomography scanner using a real-time bolus-tracking technique. Quantitative analysis was performed by determination of mean vascular attenuation at 10 regions of interest from the suprarenal aorta to the common femoral artery by one reader blinded to type and amount of contrast agent and compared using the Student t test. Image quality according to a 4-point scale was assessed in consensus by two readers blinded to type and amount of contrast medium and compared using the Mann-Whitney test. Multivariable adjustments were performed using ordinal regression analysis. RESULTS Mean total attenuation did not differ significantly between both groups (196.5 +/- 33.0 Hounsfield unit [HU] in group A and 203.1 +/- 44.2 HU in group B; P = .57 by univariate and P > .05 by multivariable analysis). Accordingly, attenuation at each region of interest was not significantly different (P > .35). Image quality was excellent or good in all patients. No significant differences in visual assessment were found comparing both contrast medium protocols (P > .05 by univariate and by multivariable analysis). CONCLUSIONS Aortoiliac aneurysm imaging can be performed with substantially reduced amounts of contrast medium using 64-detector computed tomography angiography technology.

Persistent platelet activation by passivated grafts.

Vascular grafts in canines exhibit similar healing patterns to humans in that the graft surface forms a pseudointima over time but endothelializes only near the anastomotic sites. Thus the pseudointima at the midportion of the graft may represent a nidus for persistent platelet activation. The purpose of this investigation was to examine the effect of the maturing graft surface on platelet activation. Long Dacron subcutaneous carotid to aorta grafts (50 cm x 8 mm) were placed in nine dogs. Blood samples were obtained by direct graft puncture, at the proximal and distal ends of the graft, at 1, 24, 48, 72 hours, 1, 2, 3, 4 weeks, and monthly thereafter for 8 months. Seven sham dogs had subcutaneous grafts implanted without arterial anastomoses, and blood samples were drawn from the femoral artery. Platelet counts were determined with a platelet counter. Platelet aggregation and release of adenosine triphosphate was determined with a whole blood aggregometer by use of arachidonic acid, collagen, and adenosine diphosphate as agonists. No difference was found in platelet aggregation to collagen or adenosine diphosphate stimulation across the graft, but platelets released significantly less adenosine triphosphate to collagen and adenosine diphosphate stimulation distally versus proximally. In the graft dogs a decrease in systemic platelet counts of 50% occurred from the preoperative level which persisted over 8 months (p less than 0.01). Also less response occurred to collagen and ADP stimulated platelet aggregation in the graft animals than the sham animals during the first month of study. These data suggest that significant platelet-graft interactions occur even after the graft has formed a mature pseudointima.

Matched-pair Analysis of Endovascular versus Open Surgical Repair of Abdominal Aortic Aneurysms in Young Patients at Low Risk

PURPOSE To compare clinical outcomes of endovascular and open aortic repair of abdominal aortic aneurysms (AAAs) in young patients at low risk. It was hypothesized that endovascular aneurysm repair (EVAR) compares favorably with open aneurysm repair (OAR) in these patients. MATERIALS AND METHODS Twenty-five patients aged 65 years or younger with a low perioperative surgical risk profile underwent EVAR at a single institution between April 1994 and May 2007 (23 men; mean age, 62 years+/-2.8). A sex- and risk-matched control group of 25 consecutive patients aged 65 years or younger who underwent OAR was used as a control group (23 men; mean age, 59 years+/-3.9). Patient outcomes and complications were classified according to Society of Vascular Surgery/International Society for Cardiovascular Surgery reporting standards. RESULTS Mean follow-up times were 7.1 years+/-3.2 after EVAR and 5.9 years+/-1.8 after OAR (P=.1020). Total complication rates were 20% after EVAR and 52% after OAR (P=.0378), and all complications were mild or moderate. Mean intensive care unit times were 0.2 days+/-0.4 after EVAR and 1.1 days+/-0.4 after OAR (P<.0001) and mean lengths of hospital stay were 2.3 days+/-1.0 after EVAR and 5.0 days+/-2.1 after OAR (P<.0001). Cumulative rates of long-term patient survival did not differ between EVAR and OAR (P=.144). No AAA-related deaths or aortoiliac ruptures occurred during follow-up for EVAR and OAR. In addition, no surgical conversions were necessary in EVAR recipients. Cumulative rates of freedom from secondary procedures were not significantly different between the EVAR and OAR groups (P=.418). Within a multivariable Cox proportional-hazards analysis adjusted for patient age, maximum AAA diameter, and cardiac risk score, all-cause mortality rates (odds ratio [OR], 0.125; 95% CI, 0.010-1.493; P=.100) and need for secondary procedures (OR, 5.014; 95% CI, 0.325-77.410; P=.537) were not different between EVAR and OAR. CONCLUSIONS Results from this observational study indicate that EVAR offers a favorable alternative to OAR in young patients at low risk.

Aortic aneurysm pressure sensors can be of value in the acute postoperative setting.

Purpose: To report on a case that demonstrates the use and current limits of abdominal aortic pressure sensor devices. Case report: An 83-year-old, high-risk patient underwent endovascular aortic repair (EVAR) of an infrarenal aortic aneurysm (maximum aneurysm diameter: 6.5 cm) with implantation of a pressure sensor device. At the end of the procedure and on the first postoperative day, the sensor detected persistent high pressures in the aneurysm sac, indicating an endoleak that could not be visualized on the intraoperative completion angiography but was confirmed on duplex ultrasound. During repeated angiography (postoperative day 6), again no endoleak could be detected, this time corresponding with the sensor reading that was unfortunately not interrogated again before the reintervention. Conclusion: Pressure sensor devices provide a useful, additional diagnostic tool in detecting and following endoleaks after EVAR and can help guide decisions regarding reinterventions.

Simultaneous complete supraaortic debranching and thoracic aortic endografting in an angiography suite setting.

This case series reports an initial experience in three patients treated with simultaneous complete supraaortic debranching and thoracic aortic endografting in an angiography suite setting. The article focuses on logistics and structural considerations of the setting. This includes size and equipment of the angiography suite, extent and supply of conventional surgical instruments, and safety considerations. The clinical outcome of the patients is reported. This limited experience shows that simultaneous aortic arch hybrid procedures can be performed in an angiography suite setting, given the structural and logistic requirements described.

Effect of β-blocker on aneurysm sac behavior after endovascular abdominal aortic repair

Objective: This study was conducted to determine whether &bgr;‐blocker (BB) therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular abdominal aortic repair (EVAR). Methods: A total of 198 patients (mean age, 76 years) who underwent EVAR were analyzed (104 in the BB group and 94 in the non‐BB group). The primary end point was the incidence of AAA sac regression at 1 and 2 years. Results: Hypertension, coronary artery disease, and hyperlipidemia were more common in the BB group. The BB group was also more likely to have been prescribed an aspirin and a statin than the non‐BB group. The length of proximal neck was significantly longer in the non‐BB group than in the BB group. All study patients were monitored for at least 1 year after EVAR, and 2‐year follow‐up was available in 104 patients (52.5%). There was no statistically significant difference in the incidence of aneurysm sac regression in either group at 1 year (52.1% in the non‐BB group vs 45.2% in the BB group; P = .330) and 2 years (58.5% in the non‐BB group vs 64.7% in the BB group; P = .515). The difference of the change of AAA maximum diameter between two groups did not reach statistical significance at 1 year (−6.0 ± 7.0 mm in the non‐BB group vs −5.5 ± 8.1 mm in the BB group; P = .644) and 2 years (−9.0 ± 10.5 mm in the non‐BB group vs −9.0 ± 10.0 mm in the BB group; P = .977). BB therapy was not associated with increased odds of AAA sac regression. The effect of third‐generation BBs on AAA sac regression was not significant. Conclusions: BB therapy had no effect on AAA sac regression. At the present time, there is insufficient evidence to recommend BB therapy for the purpose of AAA sac regression.