[Endovascular therapy of an abdominal aortic aneurysm in a renal transplant recipient]

INTRODUCTION: The indications for endovascular aortic aneurysm repair (EVAR) are mainly established in hostile abdomen, in patients with significant comorbidities which affect the general operability of the patient and, given the necessary infrastructure, also in ruptured aneurysm. Along to those, we present another possible indication in the presence of a kidney allograft in patients with aortic aneurysm. METHODS: Based on a case report of aorto-biiliac stent-graft repair of an infrarenal aortic aneurysm in a patient with renal allograft, a systematic review of the literature was performed of all similar cases concerning surgical therapy in this constellation. RESULTS: EVAR was performed using an aorto-biiliac system (Zenith) Trifab, COOK) in a 61-year-old male patient 11 years after heterotopic renal allotransplantation in the right iliac fossa. Preoperative renal function was normal. Because the donor renal artery was anastomosed to the recipient's external iliac artery the stent-graft was implanted from the left common femoral artery to minimize temporary allograft ischemia. The intra- and postoperative course was uneventful with a follow-up of presently 12 months. A primary type-II endoleak (retroleak from a lumbar artery) is being treated conservatively so far with embolization being a future option. At present there are 15 cases of EVAR in renal allograft patients that have been reported, all of them being successful. DISCUSSION: All data existing in the literature reported to date as well as our own experience justify the first choice of EVAR in morphologically suitable cases. One major advantage of EVAR in this constellation is the avoidance of aortic cross clamping which poses the graft at risk of ischemia. Long-term results will be most important for definite assessment of EVAR. However, contrast media application during the operation and for CT surveillance should be considered as a major disadvantage.

Female patients with atherosclerotic lesions of the lower limbs. Not all are alike

BACKGROUND: Data on female patients with atherosclerotic peripheral arterial disease (PAD) are scarce, and limited primarily to the elderly population with multilevel disease. In this longitudinal observational study we compare female patients below 60 years of age with isolated lesions at the aortic bifurcation or focal superficial femoral artery disease. PATIENTS AND METHODS: Analysis is based on consecutive series of 43 female patients with PAD limited to the aortoiliac bifurcation (n = 28, group I) or an isolated femoral segment at the adductor channel (n = 15, group II) seen in a tertiary referral center between 1998 and 2000. The first assessment provided baseline data, with follow up data obtained at this study. Traditional risk factors, carotid artery disease and clinical outcome (mortality, cardiovascular events, vascular re-intervention rate, PAD progression) were evaluated over an interval of 5 (2 to 8) years. RESULTS: Female patients with aortic disease [group I] were younger (51.8 +/- 7.7 vs. 56.7 +/- 7.6 years in group II; p = 0.048), presented a more masculine phenotype, and smoked significantly more often (82% vs. 40%; p = 0.007). Arterial hypertension and diabetes mellitus were more common in group II, though it missed statistical significance (p = 0.068 and p = 0.085). Cardiovascular and limb outcome were comparable in both groups of female patients, while carotid artery disease was more severe in group I (i.e., carotid plaques in 71 vs. 53%). CONCLUSION: Our data support previous findings that cigarette smoking is a stronger risk factor for aortic disease as compared to femoral disease in younger female patients, with the strongest effect of smoking on a localized region of the aortic bifurcation.

Small is beautiful: why profundaplasty should not be forgotten

BACKGROUND: Surgical profundaplasty (SP)is used mainly as an adjunct to endovascular management of peripheral vascular disease (PAD) today. Results from earlier series of profundaplasty alone have been controversial, especially regarding its hemodynamic effect. The question is: Can profundaplasty alone still be useful? Our aim was to evaluate its role in the modern management of vascular patients. METHODS: This was a retrospective outcome study. A consecutive series of 97 patients (106 legs) from January 2000 through December 2003 were included. In 55 (52%) legs, the superficial femoral artery was occluded. These patients were included in the current analysis. Of these patients 14 (25%) were female. Mean age was 71 ((11) years. Nineteen (35%) were diabetic. The indication for operation was claudication in 29 (53%), critical leg ischemia (CLI) in 26 (47%), either with rest pain in 17 (31%), or ulcer/gangrene in 9 (16%). Endarterectomy with patch angioplasty with bovine pericardium was performed in all cases. Mean follow-up was 33 ( 14 months. Mean preoperative ankle brachial index (ABI) was 0.6. Sustained clinical efficacy was defined as upward shift of 1 or greater on the Rutherford scale without repeat target limb revascularization (TLR) or amputation. Mortality, morbidity, need for TLR, or amputation were separate endpoints. RESULTS: Postoperatively, ABI was significantly improved (mean = 0.7), in 24 (44%) by more than 0.15. At three years, cumulative clinical success rate was 80%. Overall, patients with claudication had a better outcome than those with CLI (p = 0.04). Two (4%) major amputations and 2 (4%) minor ones were performed, all in patients with CLI. None of the 9 (16%) ulcers healed. CONCLUSION: Profundaplasty is still a valuable option for patients with femoral PAD and claudication without tissue loss. It is a straightforward procedure that combines good efficacy with low complication rates. Further endovascular treatment may be facilitated. It is not useful for patients with the combination of critical ischemia and tissue loss.

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.

Cerebral revascularization model in a swine

The purpose of this study was to analyze the suitability of the cerebral vasculature of the pig regarding a revascularization procedure. In two 60 kg pigs the femoral artery was exposed and canulated for selective angiography and interventional procedures. After the angiography, the pigs were brought to the animal OR for craniotomy and analysis of the intracranial cerebral arteries and the surgical exposure of the carotid arteries under the microscope. Angiography demonstrated the presence of a true internal-, external carotid artery and vertebral arteries. Both the vertebral and internal carotid arteries are feeding a rete mirabilis both at the cranial base and the cranio-cervical junction. At these sites further advancement of the angiography catheter was not possible. Out of these rete mirabilis, an intracranial carotid artery and an intracranial vertebral artery were formed, respectively. The intracranial cerebral vessels were of the dimension of 1 mm and less. The extracranial portion of the internal carotid artery was 2.5 mm of diameter. From these findings, we conclude that a direct cerebral revascularization procedure of the intracranial vessels is not possible in the swine. However, a global revascularization procedure on the extracranial portion of the internal carotid artery is thus feasible, both using a low- and high-flow anastamosis technique.

Pulse contour analysis: a valid assessment of central arterial stiffness in children?

In adults the contour analysis of peripheral pressure waves in the upper limb reflects central aortic stiffness. Here, we wanted to demonstrate the appropriateness of pulse contour analysis to assess large artery stiffness in children. Digital volume pulse analysis, with the computation of the stiffness index and pulse wave velocity between carotid and femoral artery, were simultaneously determined in 79 healthy children between 8 years and 15 years (mean age 11.4 years, 32 girls). The stiffness index of 42 healthy adults (mean age 45.6 years, 26 women) served as control. Pulse wave velocity between carotid and femoral artery was directly correlated with systolic pressure and mean blood pressure, as well as with pulse pressure. The results from the stiffness index of children revealed the expected values extrapolated from the linear regression of adulthood stiffness index vs. age. Childhood stiffness index positively correlated with pulse wave velocity (r(2) = 0.07, P = 0.02) but not with blood pressure parameters. The exclusion of individuals with an increased vascular tone, as indicated by a reflexion index > 90%, improved the correlation between stiffness index and pulse wave velocity (r(2) = 0.13, P = 0.001). Our data indicate that digital volume pulse-based analysis has limitations if compared with pulse wave velocity to measure arterial stiffness, mostly in patients with a high vascular tone.

Whole body postmortem angiography with a high viscosity contrast agent solution using poly ethylene glycol as contrast agent dissolver

Postmortem minimal invasive angiography has already been implemented to support virtual autopsy examinations. An experimental approach in a porcine model to overcome an initially described artificial tissue edema artifact by using a poly ethylene glycol (PEG) containing contrast agent solution showed promising results. The present publication describes the first application of PEG in a whole corpse angiographic CT examination. A minimal invasive postmortem CT angiography was performed in a human corpse utilizing the high viscosity contrast agent solution containing 65% of PEG. Injection was carried out via the femoral artery into the aortic root in simulated cardiac output conditions. Subsequent CT scanning delivered the 3D volume data of the whole corpse. Visualization of the human arterial anatomy was excellent and the contrast agent distribution was generally limited to the arterial system as intended. As exceptions an enhancement of the brain, the left ventricular myocardium and the renal cortex became obvious. This most likely represented the stage of centralization of the blood circulation at the time of death with dilatation of the precapillary arterioles within these tissues. Especially for the brain this resulted in a distinctively improved visualization of the intracerebral structures by CT. However, the general tissue edema artifact of postmortem minimal invasive angiography examinations could be distinctively reduced.

Complications associated with the arterial puncture closure device--Angio-Seal

BACKGROUND: Arterial puncture closure devices (APCD) are frequently used after cardiac catheterization. Here, the diagnosis and therapy of femoral artery complications after the use of the Angio-Seal APCD is reported. PATIENTS AND METHODS: The Angio-Seal APCD was deployed in 1600 patients undergoing transfemoral catheterization. RESULTS: In 7 of 1600 cases (0.4%) vascular complications occurred following Angio-Seal deployment. Diagnosis was made by duplex sonography. Intraoperative findings consisted of a complete occlusion with dissection of the femoral artery in all patients. In 6 cases, the femoral bifurcation had to be reconstructed after endarterectomy. Follow-up is complete with a mean of 6 months. CONCLUSION: The Angio-Seal device should not be used for closure of the superficial femoral artery and in patients with severe arteriosclerosis. The application of arteriography as well as the use of ultrasound-guided puncture is advisable. In all cases, surgical intervention was successful and an adequate therapy for management of complications.

Does aortic crossclamping during the cooling phase affect the early clinical outcome of acute type A aortic dissection?

OBJECTIVES: The purpose of this study is to evaluate the effects of crossclamping the ascending aorta in acute type A aortic dissection during the cooling phase for deep hypothermic arrest on early clinical outcome. METHODS: The records of 275 consecutive patients who underwent surgery for acute type A aortic dissection were reviewed. Ten patients have been excluded. Overall, 265 patients who underwent surgery under deep hypothermia and circulatory arrest in the "open technique" were divided retrospectively into two groups: those who underwent surgery with crossclamping of the ascending aorta during the cooling phase at the begin of the procedure (group 1, n = 191; 72.1 %) and those in whom the aorta was not clamped (group 2, n = 74; 27.9 %). RESULTS: Preoperative characteristics were similar in both groups. In group 1, femoral artery cannulation, composite graft repair, and aortic arch replacement were significantly more frequent. In-hospital mortality was 15.2 % in group 1 and 17.6 % in group 2 (P = not significant). Neurologic deficits were observed in 9.4% in group 1 and in 10.8% in group 2 (= not significant). There were no significant differences in clinical outcome between the two groups of patients. CONCLUSIONS: This study demonstrates that both options, aortic crossclamping or noclamping, may be used during the induction of deep hypothermia to repair acute type A aortic dissections with similar early clinical outcome. For the selection of the most appropriate technique, we recommend case by case evaluation, weighing the potential risks and benefits of aortic crossclamping.

Generalized dilating diathesis in patients with popliteal arterial aneurysm

BACKGROUND: Aim of this study was to analyse the relationship between popliteal artery aneurysm (PAA) and generalized arteriomegaly. PATIENTS AND METHODS: In this consecutive serie, thirty-three patients (1 woman, mean age 69.7 +/- 9.6 years) undergoing PAA repair between 1996 and 2000 agreed to participate in a duplex screening program to assess the diameters of the infrarenal abdominal aorta, common and external iliac, common and superficial femoral and contralateral popliteal arteries as well as common carotid and brachial arteries. RESULTS: The prevalence of arteriomegaly and aneurysmal disease, respectively, was as follows: abdominal aorta 15/33 (45.5%) and 8/33 (24.2%), common iliac artery 34/66 (51.5%) and 23/66 (34.8%), common femoral artery 55/66 (83.3%) and 7/66 (10.6%) as well as contralateral popliteal artery 7/33 (21.2%) 15/33 (45.5%). Significantly larger carotid artery diameters were found comparing PAA patients with age- and body surface adjusted healthy controls (p < 0.001). Furthermore, patients with multiple peripheral arterial aneurysms had significantly larger diameters of the brachial (p < 0.02) and external iliac (p < 0.005). CONCLUSIONS: Our findings support the hypothesis of a diathesis for a generalized arteriomegaly with a predilection for further aneurysms of the abdominal aorta, iliac arteries, femoral and contralateral popliteal arteries in patients with PAA.

Die operative Behandlung der Azetabulum-T-Fraktur über eine chirurgische Hüftluxation oder einen Stoppa-Zugang. [Operative treatment of T-type fractures of the acetabulum via surgical hip dislocation or Stoppa approach]

OBJECTIVE: Anatomic reduction and stable fixation by means of tissue- preserving surgical approaches. INDICATIONS Displaced acetabular fractures. Surgical hip dislocation approach with larger displacement of the posterior column in comparison to the anterior column, transtectal fractures, additional intraarticular fragments, marginal impaction. Stoppa approach with larger displacement of the anterior column in comparison to the posterior column. A combined approach might be necessary with difficult reduction. CONTRAINDICATIONS Fractures > 15 days (then ilioinguinal or extended iliofemoral approaches). Suprapubic catheters and abdominal problems (e.g., previous laparotomy due to visceral injuries) with Stoppa approach (then switch to classic ilioinguinal approach). SURGICAL TECHNIQUE: Surgical hip dislocation: lateral decubitus position. Straight lateral incision centered over the greater trochanter. Entering of the Gibson interval. Digastric trochanteric osteotomy with protection of the medial circumflex femoral artery. Opening of the interval between the piriformis and the gluteus minimus muscle. Z-shaped capsulotomy. Dislocation of the femoral head. Reduction and fixation of the posterior column with plate and screws. Fixation of the anterior column with a lag screw in direction of the superior pubic ramus. Stoppa approach: supine position. Incision according to Pfannenstiel. Longitudinal splitting of the anterior portion of the rectus sheet and the rectus abdominis muscle. Blunt dissection of the space of Retzius. Ligation of the corona mortis, if present. Blunt dissection of the quadrilateral plate and the anterior column. Reduction of the anterior column and fixation with a reconstruction plate. Fixation of the posterior column with lag screws. If necessary, the first window of the ilioinguinal approach can be used for reduction and fixation of the posterior column. POSTOPERATIVE MANAGEMENT: During hospital stay, intensive mobilization of the hip joint using a continuous passive motion machine with a maximum flexion of 90 degrees . No active abduction and passive adduction over the body's midline, if a surgical dislocation was performed. Maximum weight bearing 10-15 kg for 8 weeks. Then, first clinical and radiographic follow-up. Deep venous thrombosis prophylaxis for 8 weeks postoperatively. RESULTS: 17 patients with a mean follow-up of 3.2 years. Ten patients were operated via surgical hip dislocation, two patients with a Stoppa approach, and five using a combined or alternative approach. Anatomic reduction was achieved in ten of the twelve patients (83%) without primary total hip arthroplasty. Mean operation time 3.3 h for surgical hip dislocation and 4.2 h for the Stoppa approach. Complications comprised one delayed trochanteric union, one heterotopic ossification, and one loss of reduction. There were no cases of avascular necrosis. In two patients, a total hip arthroplasty was performed due to the development of secondary hip osteoarthritis.

Whole-body vibration dosage alters leg blood flow

The effect of whole-body vibration dosage on leg blood flow was investigated. Nine healthy young adult males completed a set of 14 random vibration and non-vibration exercise bouts whilst squatting on a Galileo 900 plate. Six vibration frequencies ranging from 5 to 30 Hz (5 Hz increments) were used in combination with a 2.5 mm and 4.5 mm amplitude to produce twelve 1-min vibration bouts. Subjects also completed two 1-min bouts where no vibration was applied. Systolic and diastolic diameters of the common femoral artery and blood cell velocity were measured by an echo Doppler ultrasound in a standing or rest condition prior to the bouts and during and after each bout. Repeated measures MANOVAs were used in the statistical analysis. Compared with the standing condition, the exercise bouts produced a four-fold increase in mean blood cell velocity (P<0.001) and a two-fold increase in peak blood cell velocity (P<0.001). Compared to the non-vibration bouts, frequencies of 10-30 Hz increased mean blood cell velocity by approximately 33% (P<0.01) whereas 20-30 Hz increased peak blood cell velocity by approximately 27% (P<0.01). Amplitude was additive to frequency but only achieved significance at 30 Hz (P<0.05). Compared with the standing condition, squatting alone produced significant increases in mean and peak blood cell velocity (P<0.001). The results show leg blood flow increased during the squat or non-vibration bouts and systematically increased with frequency in the vibration bouts.

Incidence and clinical implications of stent fractures of the Xpert self-expanding nitinol stent in infrainguinal arteries

BACKGROUND: Different stents in infrainguinal arteries have recently been associated with stent fractures and unfavorable clinical outcome, although data is limited regarding fractures of the Xpert selfexpanding nitinol stent. Thus, purpose of the present investigation was to evaluate its incidence and clinical implications in lower limb arteries. PATIENTS AND METHODS: Fifty-three consecutive patients (53 limbs) with peripheral arterial disease underwent secondary Xpert stent implantation due to suboptimal primary balloon angioplasty (PTA). Median age was 76 years. Stent fractures were evaluated by plain X-ray at median follow-up of 16 months. Stent patency was assessed by duplex ultrasound and sustained clinical improvement was defined as improvement of the ABI of > or = 0.10 together with improvement of at least one Rutherford class above the baseline finding throughout follow-up. RESULTS: Median length of femoropopliteal and infrapopliteal lesion was 3.0 and 2.3 cm, respectively. Sixtyfive stents were implanted in 43 limbs with femoropopliteal and 10 stents in 10 limbs with infrapopliteal lesion, respectively. Stent fractures occurred in 3 of 43 limbs (7.0%) of patients with femoropopliteal lesion with stent-based fracture rate of 4.6%. All fractured stents showed multiple struts fractures and occurred in the distal and middle superficial femoral artery. No stent fracture was observed in infrapopliteal lesions. The fractured stents were not associated with any clinical deterioration. Sustained clinical improvement was 71.0% and 54.6% for femoropopliteal and infrapopliteal lesions, respectively. Stent patency assessed by duplex was 65.2 and 63.9% for femoropopliteal and infrapopliteal lesions, respectively. CONCLUSIONS: Fractures of the Xpert stent were seldom and not associated with unfavorable clinical outcome at midterm follow-up.

Chronic critical leg ischemia: revascularization of the isolated popliteal segment in comparison with femoro-distal bypass

Several patients with chronic critical limb ischemia show angiographically an isolated popliteal segment (IPS) and a single calf vessel (SCV) with no direct communication to the former. In this situation a bypass can be inserted from the common femoral artery to the IPS or to the SCV. The results of 73 bypass procedures--40 to an isolated popliteal segment and 33 to a single calf vessel for limb salvage--were prospectively evaluated. Eighty percent of the grafts were performed with an autogenous saphenous vein (ASV), the rest with a thin wall polytetrafluoroethylene (PTFE) prosthesis. The mean age of our patients was 75 years and many suffered from cardiovascular disease. The operative mortality rate was 3% and the mean postoperative survival 32 months. Three year patency and limb salvage rates for ASV grafts was 83% and 87% (IPS) respectively 77% and 76% (MCV); for PTFE grafts 58% and 88% (IPS) respectively 17% and 50% (MCV). There was no significant difference found in patency and limb salvage rates of the two procedures if the graft was an autogenous saphenous vein (p > 0.05). The PTFE prosthesis was only suitable for grafts inserted to the isolated popliteal segment.

C1 esterase inhibitor reduces lower extremity ischemia/reperfusion injury and associated lung damage

BACKGROUND Ischemia/reperfusion injury of lower extremities and associated lung damage may result from thrombotic occlusion, embolism, trauma, or surgical intervention with prolonged ischemia and subsequent restoration of blood flow. This clinical entity is characterized by high morbidity and mortality. Deprivation of blood supply leads to molecular and structural changes in the affected tissue. Upon reperfusion inflammatory cascades are activated causing tissue injury. We therefore tested preoperative treatment for prevention of reperfusion injury by using C1 esterase inhibitor (C1 INH). METHODS AND FINDINGS Wistar rats systemically pretreated with C1 INH (n = 6), APT070 (a membrane-targeted myristoylated peptidyl construct derived from human complement receptor 1, n = 4), vehicle (n = 7), or NaCl (n = 8) were subjected to 3h hind limb ischemia and 24h reperfusion. The femoral artery was clamped and a tourniquet placed under maintenance of a venous return. C1 INH treated rats showed significantly less edema in muscle (P<0.001) and lung and improved muscle viability (P<0.001) compared to controls and APT070. C1 INH prevented up-regulation of bradykinin receptor b1 (P<0.05) and VE-cadherin (P<0.01), reduced apoptosis (P<0.001) and fibrin deposition (P<0.01) and decreased plasma levels of pro-inflammatory cytokines, whereas deposition of complement components was not significantly reduced in the reperfused muscle. CONCLUSIONS C1 INH reduced edema formation locally in reperfused muscle as well as in lung, and improved muscle viability. C1 INH did not primarily act via inhibition of the complement system, but via the kinin and coagulation cascade. APT070 did not show beneficial effects in this model, despite potent inhibition of complement activation. Taken together, C1 INH might be a promising therapy to reduce peripheral ischemia/reperfusion injury and distant lung damage in complex and prolonged surgical interventions requiring tourniquet application.