Editor's Choice - Comparison of Renal Outcomes in Patients Treated by Zenith® Fenestrated and Zenith® Abdominal Aortic Aneurysm Stent grafts in US Prospective Pivotal Trials.

OBJECTIVE/BACKGROUND: Fenestrated endovascular repair (FEVAR) has been used to treat complex abdominal aortic aneurysms (AAAs). The risk of renal function deterioration compared with infrarenal endovascular aortic repair (EVAR) has not been determined. METHODS: Patients with preserved renal function (estimated glomerular filtration rate [eGFR] > 45 mL/minute) enrolled in two prospective, non-randomised studies evaluating Zenith fenestrated and AAA stent grafts were matched (1:2) by propensity scores for age, sex, hypertension, diabetes, and pre-operative eGFR. Sixty-seven patients were treated by FEVAR and 134 matched controls treated by EVAR. Mean follow-up was 30 ± 20 months. Outcomes included acute kidney injury (AKI) defined by RIFLE and changes in serum creatinine (sCr), eGFR, and chronic kidney disease (CKD) staging up to 5 years. RESULTS: AKI at 1 month was similar between groups, with > 25% decline in eGFR observed in 5% of FEVAR and 9% of EVAR patients (p = .39). There were no significant differences in > 25% decline in eGFR at 2 years (FEVAR 20% vs. EVAR 20%; p > .99) or 5 years (FEVAR 27% vs. EVAR 50%; p = .50). Progression to stage IV-V CKD was similar at 2 years (FEVAR 2% vs. EVAR 3%; p > .99) and 5 years (FEVAR 7% vs. EVAR 8%; p > .99), with similar sCr and eGFR up to 5 years. During follow-up, there were more renal artery stenosis/occlusions (15/67 [22%] vs. 3/134 [2%]; p < .001) and renal related re-interventions (12/67 [18%] vs. 4/134 [3%]; p < .001) in patients treated by FEVAR. Rate of progression to renal failure requiring dialysis was low and identical in both groups (1.5% vs. 1.5%; p > .99). CONCLUSION: Aortic repair with FEVAR and EVAR was associated with similar rates of renal function deterioration in patients with preserved pre-operative renal function. Renal related re-interventions were higher following FEVAR, although net changes in renal function were similar in both groups.

Chyloptysis (chylous sputum) due to thoracic lymphangiectasis with successful surgical correction.

A 73-year-old woman with a two-year history of recurrent episodes of respiratory distress is described. The finding of an elevated triglyceride value of 23.4 mmol/L (2072 mg/dL) and a normal cholesterol value in her sputum led to the correct diagnosis of chyloptysis after lymphangiography was performed. It is thought that congenital incompetence of the lymphatic valves was the cause of chyloptysis.

Diagnosis and Treatment of Venous Malformations. Consensus Document of the International Union of Phlebology (IUP): updated 2013.

Venous malformations (VMs) are the most common vascular developmental anomalies (birth defects) . These defects are caused by developmental arrest of the venous system during various stages of embryogenesis. VMs remain a difficult diagnostic and therapeutic challenge due to the wide range of clinical presentations, unpredictable clinical course, erratic response to the treatment with high recurrence/ persistence rates, high morbidity following non-specific conventional treatment, and confusing terminology. The Consensus Panel reviewed the recent scientific literature up to the year 2013 to update a previous IUP Consensus (2009) on the same subject. ISSVA Classification with special merits for the differentiation between the congenital vascular malformation (CVM) and vascular tumors was reinforced with an additional review on syndrome-based classification. A "modified" Hamburg classification was adopted to emphasize the importance of extratruncular vs. truncular sub-types of VMs. This incorporated the embryological ongm, morphological differences, unique characteristics, prognosis and recurrence rates of VMs based on this embryological classification. The definition and classification of VMs were strengthened with the addition of angiographic data that determines the hemodynamic characteristics, the anatomical pattern of draining veins and hence the risk of complication following sclerotherapy. The hemolymphatic malformations, a combined condition incorporating LMs and other CVMs, were illustrated as a separate topic to differentiate from isolated VMs and to rectify the existing confusion with name-based eponyms such as Klippei-Trenaunay syndrome. Contemporary concepts on VMs were updated with new data including genetic findings linked to the etiology of CVMs and chronic cerebrospinal venous insufficiency. Besides, newly established information on coagulopathy including the role of D-Dimer was thoroughly reviewed to provide guidelines on investigations and anticoagulation therapy in the management of VMs. Congenital vascular bone syndrome resulting in angio-osteo-hyper/hypotrophy and (lateral) marginal vein was separately reviewed. Background data on arterio-venous malformations was included to differentiate this anomaly from syndromebased VMs. For the treatment, a new section on laser therapy and also a practical guideline for follow up assessment were added to strengthen the management principle of the multidisciplinary approach. All other therapeutic modalities were thoroughly updated to accommodate a changing concept through the years.

Gene transfer of manganese superoxide dismutase reverses vascular dysfunction in the absence but not in the presence of atherosclerotic plaque.

Impaired endothelium-dependent vasorelaxation (EDVR) is observed in hypercholesterolemia both in the presence and absence of morphological abnormalities and may be due to superoxide anions. Our aim was to assess the effect of gene transfer of manganese superoxide dismutase (MnSOD) to blood vessels from hypercholesterolemic animals with and without atherosclerotic plaque and to compare the effects of endothelial nitric oxide synthase (eNOS) and MnSOD over-expression on vascular dysfunction in the setting of atherosclerosis. Rabbits received a high-cholesterol diet for 10 weeks, resulting in abnormal EDVR in the absence of plaque in the carotids and the presence of plaque in the aorta. In Group 1, adenoviral vectors encoding MnSOD (AdMnSOD) or beta-galactosidase (Ad(beta)gal) were delivered to the carotid arteries in vivo. Four days later, transgene expression and vascular reactivity were assessed. In Group 2, segments of the aorta were transduced ex vivo with AdMnSOD, AdeNOS or both. Transgene expression and vascular reactivity were assessed 24 hr later. In Group 1, MnSOD expression was detected in AdMnSOD-ransduced vessels and impaired EDVR was reversed in the absence of atherosclerotic plaque. In Group 2 (with atherosclerotic plaque present), MnSOD and eNOS expression were detected by western analysis, and eNOS, but not MnSOD over-expression, improved EDVR whereas simultaneous over-expression of eNOS and MnSOD was no better than eNOS alone. Adenovirus-mediated gene transfer of MnSOD to nonatherosclerotic carotid arteries, but not atherosclerotic aorta, normalizes EDVR. eNOS gene transfer improves EDVR, even in the presence of plaque.

Enhanced endothelium-dependent relaxations after gene transfer of recombinant endothelial nitric oxide synthase to rabbit carotid arteries.

We tested the effects of overexpression of the endothelial nitric oxide synthase (eNOS) gene in the normal arterial wall by adenoviral-mediated gene transfer. Rabbit carotid arteries were surgically isolated and exposed to adenoviral vectors encoding eNOS (AdeNOS) or beta-galactosidase (Ad betaGal) on the contralateral side. Vector solutions at a concentration of 1 x 10(10) plaque forming units/mL were instilled for 20 minutes before restoration of flow. Arteries were harvested 4 days later for immunostaining, measurement of cGMP, and vasomotor studies. Endothelium-specific gene transfer was confirmed by staining for beta-galactosidase in the Ad betaGal arteries. Immunostaining of en face endothelial cell imprints from AdeNOS-transduced arteries with a monoclonal antibody to eNOS showed increased immunoreactivity. Basal cGMP levels were significantly greater in the AdeNOS-transduced arteries (18.4+/-4.6 versus 4.2+/-0.5 pmol/mg protein; P<.05). Contractions to phenylephrine were significantly reduced in the AdeNOS-transduced arteries (area under curve, 106+/-5 versus 119+/-7; P<.05), but in the presence of the eNOS inhibitor, N(G)-monomethyl-L-arginine (L-NMMA, 3 x 10(-4) mol/L), there was no difference between the two (area under curve, 148+/-5 versus 153+/-6; P=NS). Relaxations to acetylcholine obtained during submaximal contractions to phenylephrine were significantly enhanced in the AdeNOS-transduced arteries (EC50, 7.45+/-0.05 versus 7.23+/-0.03; P<.05). We conclude that overexpression of eNOS in the endothelium results in diminished contractile responses, as well as enhanced endothelium-dependent relaxations. These findings imply a possible role for vascular eNOS gene transfer in the treatment of vasospasm and endothelial dysfunction.

Ex vivo gene transfer of endothelial nitric oxide synthase to atherosclerotic rabbit aortic rings improves relaxations to acetylcholine.

Cholesterol feeding results in impaired endothelium dependent vasorelaxation. The role of nitric oxide in this process is unclear. The aim of this study was to evaluate the role of nitric oxide in cholesterol-induced vasomotor dysfunction by examining the effect of overexpression of eNOS in the hypercholesterolemic rabbit aorta on vascular reactivity. Vascular rings from the thoracic aorta of hypercholesterolemic rabbits were exposed ex vivo either to an adenoviral vector encoding endothelial nitric oxide synthase (AdeNOS) or Escherichia coli beta Galactosidase (AdbetaGal). Transgene expression was examined by histochemistry for beta galactosidase, immunohistochemistry for eNOS and cyclic GMP measurements and vasomotor studies were performed. Transgene expression was found to localize to the endothelium and adventitia. cGMP levels were significantly greater in AdeNOS compared to AdbetaGal transduced rings. Acetylcholine mediated relaxation was significantly impaired in cholesterol fed rabbits and was markedly improved by overexpression of eNOS. These results suggest that reduced NO bioavailability observed in cholesterol-induced vascular dysfunction can be partially overcome by eNOS gene transfer.

Ibuprofen in experimental vascular surgery.

Animal studies have been conducted to determine the effectiveness of ibuprofen in reducing early platelet deposition on small diameter (4 mm) Gore-Tex (polytetrafluoroethylene) arterial grafts and larger (10 mm) Gore-Tex grafts placed in the inferior vena cava. These studies demonstrated a significant reduction in platelet deposition at one and three hours. Additional studies of animals undergoing treatment with ibuprofen and subjected to arterial replacement with 1 or 4 mm Gore-Tex grafts demonstrated enhanced patency at 30 days. Cautious evaluation of ibuprofen as an adjunct in vascular surgery appears warranted.

Lymphoscintigraphy and lymphangiography of lymphangiectasia.

Chronic genital edema secondary to lymphangiectasia and chylous reflux in a 23-yr-old man with Noonan syndrome was investigated by 99mTc sulfur nanocolloid lymphoscintigraphy and bipedal contrast lymphangiography. Lymphoscintigraphy showed a delayed lymphatic flow pattern in the pelvis, abdomen and chest consistent with lymphangiectasia and abnormal lymphatic flow dynamics. Lymphangiography showed dilated and tortuous abnormal lymphatics in the abdomen and pelvis. Ligation of incompetent retroperitoneal lymph vessels and lymphaticovenous anastamosis were performed, resulting in clinical improvement. Lymphangiectasia has been described previously in Noonan syndrome, but it is relatively uncommon below the diaphragm. This case demonstrates the use of lymphoscintigraphy and lymphangiography in providing important physiological and anatomical information before surgical intervention. Careful presurgical planning using such tests also allows the most appropriate operation to be performed.

Lymphoscintigraphy in lymphedema: an aid to microsurgery.

The role of lymphoscintigraphy, performed with 99mTc-labeled antimony sulfur colloid, in the diagnosis of lymphedema and as a test for selection of patients for microvascular operation was evaluated in 32 patients with primary and secondary lymphedema and four patients with other causes of leg edema. Lymphoscintigraphy clearly demonstrated if edema was of lymphatic origin. Five different image patterns were identified; abnormal image patterns could not be predicted from clinical history or physical findings. Quantitative evaluation of removal of the radioactive colloid from the injection site and appearance in lymph node sites and liver was of limited usefulness. Nine patients underwent various surgical procedures before or after lymphoscintigraphy. Lympho-venous anastomoses were possible only in patients who had patent lymph channels visible on lymphoscintigrams. Based on initial experience, lymphoscintigraphy seems to be useful to select patients for microvascular operation.

Successful repair of an unusual hernia associated with traumatic pubic diastasis.

A 70-year-old man had an unusual type of supravesical small bowel hernia associated with herniation of the bladder through a traumatic diastasis of the pubic symphysis. The diastasis was closed with prosthetic mesh through a preperitoneal approach. In patients in whom a scrotal hernia develops after a previous pelvic fracture, especially those with evidence of a pubic diastasis, an unusual type of hernia should be suspected. A preperitoneal surgical approach best reveals the anatomy and allows appropriate repair. The best procedure for prevention of such hernias is primary reduction of any substantial pubic diastasis, but operative intervention is not indicated in all patients.

Intrathoracic lymphangioma.

Of 14 cases of intrathoracic lymphangioma, 4 occurred in the anterior, 5 in the superior, and 4 in the posterior mediastinum. One lesion was diffuse and associated with disappearing bone disease (Gorham's disease). The anterior mediastinal lymphangiomas occurred in adults and seemed to arise from the mediastinum. They could not be distinguished from other anterior mediastinal lesions on plain film roentgenograms. The lesions of the superior mediastinum were extensions from cystic hygromas of the neck and occurred primarily in children. Recurrence was common because complete resection was not possible. Computed tomography was helpful in detecting the cervical extension and cystic nature of these lesions. Although two of the four posterior compartment lesions were isolated lymphangiomas, the other two were part of a much more extensive and generalized lymphangiomatosis that included bone lesions and subdiaphragmatic extension. Both of these latter cases were complicated by chylothorax after attempted removal of the mediastinal lymphangioma. Computed tomography and lymphangiography were helpful in determining the extent of the disease and the cystic and lymphatic nature of the mass. The patient with Gorham's disease had extensive lymphangiomatosis of the thorax and recurrent chylothorax; surgical treatment was unsuccessful. Although lymphangioma is a benign tumor, its infiltrative tendency complicates its removal and contributes to its postoperative recurrence.

Myocardial revascularization before abdominal aortic aneurysmorrhaphy: effect of coronary angioplasty.

Percutaneous transluminal coronary angioplasty (PTCA) has assumed an increasing role in the preoperative preparation of patients with an abdominal aortic aneurysm (AAA). The influence of this modality on perioperative morbidity and long-term outcome has not been substantiated. To determine the effect of PTCA, we analyzed a cohort of 2,452 patients who underwent repair of an AAA between 1980 and 1990 at our institution. We compared the cardiac morbidity, mortality, and survival of patients who had preoperative coronary revascularization by PTCA or coronary artery bypass grafting (CABG). The overall perioperative mortality for the 2,452 patients was 2.9%. Preoperative coronary revascularization was necessary in 100 patients (4.1%)--86 had CABG and 14 had PTCA. Of these 100 patients, 95% had cardiac symptoms. Patients selected for PTCA, in comparison with CABG, had significantly less three-vessel disease but not significant differences in cardiac history or ejection fraction. During the study period, the use of PTCA increased significantly. The perioperative rate of myocardial infarction for patients with prior CABG was 5.8% in comparison with 0% for those with prior PTCA. No hospital deaths occurred in either group. The median interval between coronary revascularization and repair of an AAA was 10 days for PTCA and 68 days for CABG. The 3-year survival was not statistically different between CABG (82.8%) and PTCA (92.3%) groups. The rate of late cardiac events (at 3 years) was 56.5% in the PTCA group and 27.3% in the CABG group. We conclude that PTCA as part of a highly selective approach to coronary revascularization before repair of an AAA minimizes cardiac-related events and death.(ABSTRACT TRUNCATED AT 250 WORDS)

Selection and preparation of high-risk patients for repair of abdominal aortic aneurysms.

OBJECTIVE: To discuss the most important risk factors in patients who undergo surgical repair of an abdominal aortic aneurysm (AAA). DESIGN: This update in vascular surgical repair highlights the criteria that identify high-risk patients, the useful preoperative tests, and the perioperative measures that can aid surgical recovery. MATERIAL AND METHODS: In elective repair of AAAs, high-risk patients are those with severe coronary or valvular heart disease, decompensated chronic obstructive pulmonary disease, severe cerebrovascular disease, chronic renal failure, hepatic cirrhosis with portal hypertension, and chronic hematologic disorders associated with bleeding dysfunction. Patients with unstable or severely symptomatic heart disease should undergo preoperative coronary angiography and ventriculography. Pharmacologic stress testing is recommended for patients with clinical markers of serious coronary artery disease and other medical or physical factors that prevent any type of standard exercise stress testing. RESULTS: Our experience with high-risk patients supports conventional repair of AAAs. Our preference for the midline abdominal incision in high-risk patients is substantiated by an operative mortality rate of 5.7% in comparison with a reported 7% mortality rate for nonresective therapy. Approximately one in three high-risk patients will have a serious postoperative complication, the most common of which is a cardiac event. Most patients recover after a slightly prolonged hospital stay. CONCLUSION: Despite an increased operative risk, patients with a stable medical condition and an AAA larger than 6 cm in diameter should be considered for elective repair. High-risk patients with smaller aneurysms (5 to 6 cm in diameter) should undergo efforts to stabilize or to improve their general medical condition before elective operation.

Microvascular pedal bypass for salvage of the severely ischemic limb.

Bypass to the pedal arteries was performed with use of the operating microscope and standard microsurgical technique in 37 patients with severe, chronic ischemia of a lower extremity. Twenty-one patients (57%) had three or more cardiovascular risk factors, and 22 (59%) had diabetes. Preoperative arteriography identified a pedal artery suitable for bypass in all but one patient. The greater or lesser saphenous vein was used in all patients, most frequently as a nonreversed, translocated vein graft. An arm vein was used as part of a composite graft in only one patient. No early deaths occurred, and only one patient had a perioperative myocardial infarction. Although five grafts occluded within 30 days, four were successfully revised, and 36 patients had a patent graft at the time of dismissal from the hospital. At 1 year, the primary graft patency rate (patency without revision) was 60.8%, and the secondary patency rate was 68.8%. One early and six late amputations were performed; the cumulative 1-year limb salvage rate was 82.4%. Grafts with an intraoperative flow rate of 50 ml/min or more had a better patency rate than those with a lower flow rate. The presence of diabetes did not adversely affect long-term patency. Of the 34 patients who were alive at the time of this report, 27 (79%) had a functional foot that allowed ambulation, had no rest pain, and had no substantial loss of tissue. Pedal bypass should be considered for critical, chronic ischemia, even if the patient has an increased surgical risk and advanced distal atherosclerotic disease.

Klippel-Trénaunay syndrome: spectrum and management.

OBJECTIVE: To describe a series of 252 patients with Klippel-Trénaunay syndrome (KTS), a rare congenital malformation characterized by the triad of capillary malformations, atypical varicosities or venous malformations, and bony or soft tissue hypertrophy usually affecting one extremity. MATERIAL AND METHODS: We reviewed the clinical characteristics and findings in 136 female and 116 male patients with KTS who underwent assessment at Mayo Clinic Rochester between January 1956 and January 1995. In addition, management options are discussed. RESULTS: Capillary malformations (port-wine stains) were found in 246 patients (98%), varicosities or venous malformations in 182 (72%), and limb hypertrophy in 170 (67%). All three features of KTS were present in 159 patients (63%), and 93 (37%) had two of the three features. Atypical veins, including lateral veins and persistent sciatic vein, occurred in 182 patients (72%). Operations performed in 145 patients with KTS included epiphysiodesis, stripping of varicose veins or venous malformations, excision of vascular malformations, amputations, and debulking procedures. CONCLUSION: Most patients with KTS should be managed conservatively. The clearest indication for operation is a leg length discrepancy projected to exceed 2.0 cm at skeletal maturity, which can be treated with epiphysiodesis in the growing child. If a functioning deep vein system is present, removal of symptomatic varicosities or localized superficial venous malformations in selected patients can yield good results.

The effect of preclotting on surface thrombogenicity and thromboembolic complications of Dacron grafts in the canine thoracic aorta.

Previous reports have advocated preclotting and autoclaving of Dacron grafts to prevent graft hemorrhage, yet no data delineate possible changes in surface thrombogenicity or thromboembolic risks. To assess these factors, preclotted and preclotted-autoclaved woven Dacron prostheses were implanted in the thoracic aorta of 31 dogs. Grafts were harvested 1 week to 1 month following implantation, and the thrombus-free surface of each graft was calculated by computerized morphometry. Values for thrombus-free surface were lowest in autoclaved grafts preclotted in nonheparinized blood (72%) or in heparinized blood (78%). Grafts preclotted in platelet-rich plasma and autoclaved had a thrombus-free surface value of 85%. Regular preclotted grafts or grafts without preclotting had the greatest thrombus-free surface value (97% and 99%). Distal embolization to the kidneys was detected in seven of 31 animals (23%). No emboli were found in animals with grafts that were not preclotted or if grafts were preclotted with platelet-rich plasma and autoclaved. Thrombus-free surface values were lower (p less than 0.01) in grafts with embolic complications (71% versus 91%). These data suggest that, if the risk of severe bleeding in fully heparinized patients precludes the use of a woven Dacron graft without preclotting, autoclaving a graft preclotted with platelet-rich plasma appears to be the method of choice.

Overcoming failure of venous vascular prostheses.

Thrombogenicity of graft material, low velocity of blood flow, and wall collapsibility have been cited as the main factors responsible for the high occlusion rate of vascular prostheses placed in the venous system. This study was performed to analyze the effects of measures taken to overcome each of these factors. The thrombogenicity of expanded polytetrafluoroethylene (ePTFE) was evaluated by determination of the 3-hour deposition of radionuclide-labeled platelets and fibrin on grafts placed in the infrarenal vena cava of 18 dogs. Wetting the prosthesis with heparin before implantation significantly decreased platelet deposition at the cranial anastomosis (p less than 0.025) and on the graft surface (p less than 0.01), whereas the decrease of fibrin deposition was not statistically significant. The effects of flow velocity and graft support were studied in 44 dogs subjected to iliocaval bypass. The results of these studies demonstrated that a flow-increasing arteriovenous fistula was necessary to maintain patency of ePTFE grafts (p less than 0.01) but did not enhance patency of autogenous vein grafts. External ring support of ePTFE grafts did not significantly improve early patency. Decreasing thrombogenicity by wetting the grafts with heparin and increasing the blood flow by constructing an arteriovenous fistula helps in overcoming failure of venous vascular prostheses.

Klippel-Trenaunay syndrome: the risks and benefits of vascular interventions.

Our experience with Klippel-Trenaunay syndrome (KTS), a rare congenital malformation, has increased considerably in recent years and now includes 144 patients (65 male and 79 female patients). Hemangioma was present in 137 patients (95.1%), varicosity in 110 (76.4%), and hypertrophy of the soft tissues or bones in 134 (93.1%). In most patients (71.5%) the disease involved one lower extremity. Diagnostic workup included roentgenogram to document limb length discrepancy, noninvasive arterial and venous evaluation, contrast venography, and nuclear magnetic resonance imaging. Most patients did well without treatment or with elastic compression only. Surgical treatment for the vascular malformation in KTS is rarely needed and it continues to be controversial. To evaluate the risks and benefits of vascular interventions, we examined in detail the clinical histories of nine patients who in the last decade underwent operation for a vascular malformation of the lower extremity. In seven patients we removed varicose veins or resected hemangioma of the lower extremity. Although none was cured, all five who underwent resection of varicose veins and one of the two patients who underwent resection of a hemangioma improved. Two additional patients, however, who underwent resection of varicose veins in another institution had worsening of the symptoms. In one patient we performed deep venous reconstruction for atresia of the superficial femoral vein, using the contralateral saphenous vein. Such operation in KTS has not been reported previously. The patient has a patent graft with a competent valve and clinical improvement 6 months after the operation. Although patients with severe chronic venous insufficiency, disturbing cosmetic appearance, or complications of hemangioma may benefit from surgical treatment, detailed preoperative imaging of the extremity and pelvis with magnetic resonance imaging and contrast venography is needed to decrease complications. Rarely, reconstruction for atresia or hypoplasia of the deep veins may be needed.