Andreas M. Lazaris

A multilayer stent in the aorta may not seal the aneurysm, thereby leading to rupture

The multilayer stents are occasionally used for the treatment of complicated aortic aneurysms, including thoracoabdominal aneurysms. No aneurysm-related mortality among patients treated with this technique has been described in the literature to date. We describe a case of rupture of an aortic aneurysm previously treated with a multilayer stent.

Cerebrovascular reacivity assessment in patients with carotid artery disease: a combined TCD and NIRS study.

Transcranial Doppler (TCD) and near‐infrared spectroscopy (NIRS) are two noninvasive diagnostic tools that have been shown to evaluate cerebral vasomotor reactivity by measuring changes in mean cerebral blood flow velocities (MCBFV) of proximal intracranial arteries and absolute brain‐tissue oxygen‐saturation (TOS) in microcirculation, respectively, during hemodynamic challenge. We evaluated the potential correlation between TCD and NIRS measurements of vasomotor reactivity (VMR) in patients with carotid artery disease (CARAD).

Flow-Diverting Multilayer Stents: A Promising but Questionable Solution for Aortic Pathologies:

In this issue of the JEVT, Sultan and Hynes review 55 patients with various aortic pathologies treated with the Cardiatis multilayer flow modulator or flow-diverting stents by a variety of surgeons and interventionists in 11 countries. Despite the fact that this is from a registry and not a properly conducted trial, the data and conclusions are of significant importance. This is the largest report to date with regard to the use of these stents in aortic pathologies. Since the first reported extracranial use of a flow-diverting stent in aneurysmal disease in 2008, sporadic reports have appeared in the literature with regard to their use in aortic pathologies. According to the study, extraordinarily exceptional results can exist with the use of the multilayer stent in thoracoabdominal aneurysms and type B aortic dissections up to 1-year follow-up: zero conversion to open surgery, zero admission to intensive care units postoperatively, zero paraplegia, zero visceral/renal artery occlusions, zero major perioperative bleeding (.20% of blood volumes), and zero 30-day mortality. Would this be the situation with the mid and long-term results as well, there would be almost no need for any other treatment for these extremely hazardous pathologies. But, is this method really that good? The hypothesis of aneurysm thrombosis using a low porosity bare metal stent was first described about two decades ago. Geremia et al. had observed that a metallic stent bridging an aneurysm sac might alter the flow pattern within the aneurysm, thereby promoting thrombus formation and aneurysm occlusion. At the same time, Piquet et al. described treatment of aneurysms utilizing a stent-like device that combined both metal and fabric, the so-called ‘‘coknit.’’ In patients treated with the coknit, thrombosis had been observed, while the inferior mesenteric and all the non-occluded lumbar arteries were patent. Similarly, the multilayer flow modulator stent is a bare stent system. It is structured with two interconnected superimposed layers that achieve low intra-stent porosity. A computational fluid dynamics study indicates that a stent with an overall porosity of 50% to 70% significantly reduces the inflow rate into the aneurysm sac by improving the laminar flow in the main artery and its branches. Theoretically, in an aneurysm with branches, the stent redirects the flow toward the ostia of the side branches, creating a kind of suction effect to the aneurysm itself. This allows a pressure decrease within the aneurysm sac, stasis, and formation of organized thrombus. However, this is a two-faced coin. Conflicting research data exist in the literature. Michel and colleagues have proposed that blood supply within the intraluminal aneurysm

A network meta-analysis of randomized controlled trials comparing treatment modalities for de novo superficial femoral artery occlusive lesions

Background: Treatment of superficial femoral artery (SFA) lesions remains challenging. We conducted a network meta‐analysis of randomized controlled trials aiming to explore the efficacy of treatment modalities for SFA “de novo” lesions. Methods: Eleven treatments for SFA occlusive disease were recognized. We used primary patency and binary restenosis at 12‐month follow‐up as proxies of efficacy for the treatment of SFA lesions. Results: A total of 33 studies (66 study arms; 4659 patients) were deemed eligible. In terms of primary patency, odds ratios (ORs) with 95% confidence intervals (CIs) were statistically significantly higher in drug‐eluting stent (DES; OR, 10.05; 95% CI, 3.22‐31.39), femoropopliteal bypass surgery (BPS; OR, 7.15; 95% CI, 2.27‐22.51), covered stent (CS; OR, 3.56; 95% CI, 1.33‐9.53), and nitinol stent (NS; OR, 2.83; 95% CI, 1.42‐5.51) compared with balloon angioplasty (BA). The rank order from higher to lower primary patency in the multidimensional scaling was DES, BPS, NS, CS, drug‐coated balloon, percutaneous transluminal angioplasty with brachytherapy, stainless steel stent, cryoplasty (CR), and BA. Combination therapy of NS with CR and drug‐coated balloon were the two most effective treatments, followed by NS, CS, percutaneous transluminal angioplasty with brachytherapy, cutting balloon, stainless steel stent, BA, and CR in terms of multidimensional scaling values for binary restenosis. Conclusions: DES has shown encouraging results in terms of primary patency for SFA lesions, whereas BPS still maintains its role as a principal intervention. On the contrary, BA and CR appear to be less effective treatment options.

Aortoiliac endograft-enteric fistula due to an ingested toothpick

Foreign body ingestion is not uncommon, but in most patients the object passes without sequelae. In very few patients, the ingested foreign objects may perforate the gastrointestinal tract, causing potentially life-threatening complications. Pointed ingested objects such as toothpicks are the most common. Vascular perforation due to toothpick ingestion has rarely been reported. We present a patient with lower gastrointestinal bleeding secondary to simultaneous perforation of the sigmoid colon and the right iliac limb of an aortobiiliac endograft by an ingested toothpick. This arterioenteric fistula was treated in two stages. First as a bridging operation, a stent graft was inserted into the ipsilateral limb of the previous aortoiliac endograft to control the bleeding. Second, the aortoiliac endograft was removed, the aorta was oversewn, and an extra-anatomic axillobifemoral bypass restored the flow to the lower limbs. The colon perforation was treated with a proximal temporary loop colostomy. To our knowledge, this the first case of aortoiliac endograft-enteric fistula after endovascular abdominal aortic aneurysm repair caused by this extraordinary mechanism.

Remote Ischemic Preconditioning May Attenuate Renal Ischemia-Reperfusion Injury in a Porcine Model of Supraceliac Aortic Cross-Clamping.

Aim: The effect of remote ischemic preconditioning (RIPC) in decreasing renal ischemia-reperfusion injury (IRI) during a suprarenal aortic cross-clamping was examined in a swine model. Materials and Methods: Four groups of pigs were examined: (a) ischemia-reperfusion (IR) group, renal IRI produced by 30 min of supraceliac aortic cross-clamping; (b) RIPC I group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (15 min ischemia and 15 min reperfusion); (c) RIPC II group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (3 cycles of 5 min ischemia and 5 min reperfusion); (d) sham group. Renal function was assessed before and after IRI by examining creatinine, neutrophil gelatinase-associated lipocalin (NGAL), TNF-α, malondialdehyde (MDA), cystatin C and C-reactive protein (CRP) from renal vein blood samples at specific time intervals. Results: Both RIPC groups presented significantly less impaired results compared to the IR group when considering MDA, cystatin C, CRP and creatinine. Between the two RIPC groups, RIPC II presented a better response with regard to CRP, NGAL, TNF-α, MDA and cystatin C. Conclusions: Remote IR protocols and mainly repetitive short periods of cycles of IR ameliorate the biochemical kidney effects of IRI in a model of suprarenal aortic aneurysm repair.

Effect of diabetes mellitus on the clinical outcome of lower limb arterial bypass surgery: A propensity score analysis.

Objectives Diabetic patients who undergo lower limb arterial bypass surgery are considered to have a worse clinical outcome compared to non-diabetics. The aim of the study was to test this hypothesis after applying propensity score matching analysis. Patients and methods A total of 113 consecutive lower limb bypass procedures (55 diabetic and 58 non-diabetic) were evaluated regarding their clinical outcome. Endpoints of the study included amputation-free survival, limb salvage, patency and patients’ survival up to 36 months post-procedure. After propensity score matching analysis, two new groups, diabetic and non-diabetic, of 31 limbs in each one were created, both equivalent regarding all baseline characteristics. Results Between the propensity score matching groups, the amputation-free survival was 68.8% in the non-diabetic and 37.7% in the diabetic group at 36 months (p = 0.004). Similarly, the survival was 88.6% and 57.6%, respectively, in the two groups at the same time point (p = 0.01). On the contrary, no difference was found in patency (58.3% vs. 56%) and in limb salvage rate (74.1% vs. 60.8%). Conclusions Lower limbs arterial bypass surgery has similar results regarding patency and limb salvage rate in diabetic and non-diabetic patients. On the contrary, mortality is worse in diabetic patients, this affecting negatively their amputation-free survival.

Commentary: Remote Ischemic Preconditioning: Myth or Reality?

Remote ischemic preconditioning (RIPC) has been described as a potential means of reducing ischemia–reperfusion injury (IRI) in various tissues. This mechanism has been proven mainly in animal models, but with increasing frequency, clinical studies are proposing possible analogous benefits in patients. However, questions arise with regard to the real therapeutic magnitude: is RIPC really such a useful weapon against occasionally lethal IRI? Since the first report of the possible beneficial effect of RIPC in myocardial IRI 16 years ago, hundreds of experimental studies have been published. Almost all agree that RIPC can decrease IRI in various remote tissues. Heart, liver, lung, intestine, brain, kidney, and limbs are capable of producing remote preconditioning when subjected to brief ischemia–reperfusion, but the actual mechanism through which RIPC protects remote tissues is unclear. Animal studies have suggested that the protection might be mediated either via humoral mediators or by the recruitment of a neuronal pathway, both resulting in reduced oxidative stress and preservation of mitochondrial function in ischemic tissues. To date, small clinical trials have been conducted with regard to the usefulness of RIPC in patients undergoing open heart surgery or abdominal aortic aneurysm repair (open and endovascular). The initial results have been encouraging. Three trials have examined the use of RIPC in cardiac surgery both in children and adults. In all studies, a decrease in myocardial damage was noted in RIPC groups by assessing biochemical serum markers (troponin I) or inotrope requirements. However, no significant clinical improvement was proven. As far as aortic surgery is concerned, two randomized trials, both from the same center, have now been conducted, the more recent being described by Walsh et al. in the current issue of JEVT. The first one examined the possible protection of RIPC in cardiac and renal IRI after open abdominal aortic aneurysm repair by serum biomarker assessment (troponin I and creatinine). The authors concluded that RIPC reduces the incidence of postoperative myocardial injury, myocardial infarction, and renal impairment in these patients. In the current article, Walsh et al. examined the effect of RIPC in renal and cardiac IRI in patients who had an endovascular aneurysm repair. Again, the results were promising. Remote preconditioning reduced urinary biomarkers of renal injury, although no indication of cardioprotection was found in the RIPC group. Certainly, there is evidence that RIPC could offer some protection from myocardial and renal IRI in aortic and heart surgery. Taking into consideration the positive results of other experimental studies that have examined different uses of RIPC in aortic surgery models, it seems reasonable to hypothesize that RIPC could protect other organs apart from the heart during aortic surgery. However, the use of RIPC to protect all vulnerable organs against IRI is still in the future. Further

Rehabilitation Outcome in Patients With Lower Limb Amputations Because of Arterial Occlusive Disease: Is it Worth Trying for the Lowest Possible Amputation Level? A Prospective Study

A policy of maximizing the ratio of below-knee to above-knee amputations in patients with severe nonsalvageable limb ischemia is followed. The value of this policy is examined. All the patients that were amputated in our department between 1995 and 1997 were followed up for 2 years after the operation. We correlated the amputation level with 6 different parameters: primary or secondary amputation, perioperative mortality, 2-years mortality, amputation stump healing, artificial limb fitment, and rehabilitation outcome. The results were analyzed statistically. A total of 64 patients were included in the study. The revision rate was 38% in below-knee amputees and 4% in above-knee amputees. The perioperative mortality was 22%. Two years after operation, the limb fitment rate in below-knee amputees was 95% and in above-knee amputees was 64%. The overall artificial limb fitment rate was 50%. A total of 47.6% of the living patients were capable to walk out of their house. Artificial limb fitment and rehabilitation status are greater after a below-knee than an above-knee amputation. Although the morbidity may be higher in below knee procedures, it is worth trying for the lowest level of amputation because of the better rehabilitation results in these patients.

How to do a 'roof-top' approach to the supraceliac aorta.

When access to the suprarenal aorta is required, the traditional midline transperitoneal approach is often inadequate. The retroperitoneal approach has been advocated as an alternative, but when access to the supracoeliac aorta is required, extension of the incision into the left hemithorax is occasionally inevitable. The bilateral subcostal abdominal approach with left medial visceral rotation, the so-called ‘roof-top’ approach, has been described as an alternative technique in treating type IV thoracoabdominal aortic aneurysms, claiming as its main advantage the avoidance of entering into the left thoracic cavity. We describe the ‘roof-top’ approach for treating various complex abdominal aortic pathologies characterized by a challenging proximal neck. The patient is placed in a right oblique position with the upper torso almost perpendicular to the bed and the hips placed horizontally on the operating table. The incision is an abdominal bilateral subcostal, with the left side extending to the anterior axillary line (Fig. 1a). After entering into the peritoneal cavity, the sigmoid colon is retracted medially to expose the posterior peritoneum, which is divided lateral to the sigmoid colon along the line of Toldt. A left side retroperitoneal dissection is performed posterior to the gonadal vessels, left ureter, kidney and Gerota fascia by blunt mobilization up to the diaphragm. A left medial visceral rotation follows: the right kidney and ureter, the spleen, the tail of pancreas and the stomach are rotated en bloc to the patients’ right side. The right crus that encompasses the upper portion of the abdominal aorta is divided and the supracoeliac aorta is dissected free. At this stage, the total length of the aorta is exposed from the diaphragm to its bifurcation (Fig. 1b). The patient is heparinized and the aorta is clamped in an anteroposterior fashion, at a supracoeliac level. Aneurysm repair can be undertaken using a clamp and sew technique. A standard transverse endoaneurysmorrhaphy is performed just below the lowest renal artery in juxtarenal aneurysms, or using a bevelled configuration (including some or all the orifices of the splanchnic vessels) in suprarenal or type IV thoracoabdominal aneurysms. If the orifice of the left renal artery cannot be included in the proximal anastomosis, the artery is either reimplanted or anastomosed through a synthetic jump-graft onto the aortic graft. Routine insertion of a catheter for cerebrospinal fluid drainage is not considered necessary. Using this approach, we have treated 18 patients suffering by a range of aortic pathologies requiring supracoeliac exposure, throughout a 5-year period. These included type IV thoracoabdominal aortic aneurysms (four cases), suprarenal aneurysms (four cases), juxtarenal aneurysms (seven cases) and infrarenal reoperations on abdominal aorta (three cases). Thirteen cases (72%) were elective while five patients (28%) were treated on an urgent or emergency basis. All aortic repairs were performed on a clamp and sew technique. The procedures were completed successfully in all patients. Of the 18 cases, 16 underwent supracoeliac clamping. Among these 16 cases, 14 developed a temporary elevation of serum creatinine (median value before clamping of 0.097 mmol/L to 0.172 mmol/L post-procedure), but this returned to almost the baseline value (median value at discharge 0.106 mmol/L). No paraplegia and no spleen injury requiring a splenectomy were noted.