Felix J.V. Schlösser

Management of Abdominal Aortic Aneurysms Clinical Practice Guidelines of the European Society for Vascular Surgery

Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands b Imperial College, London, UK University Hospital Innsbruck, Austria Azienda Ospedaliera di Perugia, Italy Hopital Cardiologique, CHRU de Lille, Lille, France f St Thomas’ Hospital, London, UK g St George’s Vascular Institute, London, UK Yale University School of Medicine, New Haven, Connecticut, USA University of Siena, Siena, Italy University of Poitiers, Poitiers, France

The Semmes Weinstein monofilament examination as a screening tool for diabetic peripheral neuropathy

OBJECTIVE The purpose of this systematic review is to evaluate current evidence in the literature on the efficacy of Semmes Weinstein monofilament examination (SWME) in diagnosing diabetic peripheral neuropathy (DPN). METHODS The PubMed database was searched through August 2008 for articles pertaining to DPN and SWME with no language or publication date restrictions. Studies with original data comparing the diagnostic value of SWME with that of one or more other modalities for DPN in patients with diabetes mellitus were analyzed. Data were extracted by two independent investigators. Diagnostic values were calculated after classifying data by reference test, SWME methodology, and diagnostic threshold. RESULTS Of the 764 studies identified, 30 articles were selected, involving 8365 patients. There was great variation in both the reference test and the methodology of SWME. However, current literature suggests that nerve conduction study (NCS) is the gold standard for diagnosing DPN. Four studies were identified which directly compared SWME with NCS and encompassed 1065 patients with, and 52 patients without diabetes mellitus. SWME had a sensitivity ranging from 57% (95% confidence interval [CI], 44% to 68%) to 93% (95% CI, 77% to 99%), specificity ranging from 75% (95% CI, 64% to 84%) to 100% (95% CI, 63% to 100%), positive predictive value (PPV) ranging from 84% (95% CI, 74% to 90%) to 100% (95% CI, 87% to 100%), and negative predictive value (NPV) ranging from 36% (95% CI, 29% to 43%) to 94% (95% CI, 91% to 96%). CONCLUSIONS There is great variation in the current literature regarding the diagnostic value of SWME as a result of different methodologies. To maximize the diagnostic value of SWME, a three site test involving the plantar aspects of the great toe, the third metatarsal, and the fifth metatarsals should be used. Screening is vital in identifying DPN early, enabling earlier intervention and management to reduce the risk of ulceration and lower extremity amputation.

Aneurysm Rupture after EVAR: Can the Ultimate Failure be Predicted?

OBJECTIVES To provide insight into the causes and timing of AAA rupture after EVAR. DESIGN Original data regarding AAA ruptures following EVAR were collected from MEDLINE and EMBASE databases. Data were extracted systematically and patient and procedural characteristics were analyzed. RESULTS 270 patients with AAA ruptures after EVAR were identified. Causes of rupture included endoleaks (in 160: type IA 57, type IB 31, type II 23, type III 26, type IV 0, endotension 9, unspecified 14), graft migration 41, graft disconnection 11 and infection 6. Most of the described AAA ruptures occurred within 2-3 years after EVAR. Mean initial AAA diameter was relatively large (65 mm). No abnormalities were present in 41 patients during follow-up before rupture. Structural graft failure was described in 96 and a fatal course in 119 patients. CONCLUSIONS Focus of surveillance on the first 2-3 years after EVAR may possibly reduce the AAA rupture rate, especially in patients with increased risk of early rupture (relatively large initial AAA diameter or presence of endoleak or graft migration). Better stent-graft durability and longevity is required to further reduce the AAA rupture risk after EVAR. Complete prevention will however remain challenging since AAA rupture may occur even if no predisposing abnormalities are present.

Thoracic endovascular aortic repair with the chimney graft technique

OBJECTIVE This study was conducted to provide insight into the safety, applicability, and outcomes of thoracic endovascular aortic repair (TEVAR) with the chimney graft technique. METHODS Original data regarding the chimney technique in TEVAR in the emergent and elective setting were collected from MEDLINE, Embase, and Scopus databases. All variables were systematically extracted and included in a database. Patient and procedural characteristics, details, and outcomes were analyzed. RESULTS In total, 94 patients with 101 chimney-stented aortic arch branches were analyzed, consisting of the brachiocephalic artery in 20, the left common carotid artery in 48, and the left subclavian artery in 33. Balloon-expandable stents were used in 36% and self-expandable stents in 64% for the aortic side branch. The interventions were elective in 72% and emergent in 28%. Technical success was achieved in 98% in elective and emergent settings combined. Endoleaks were described in 18%; with type Ia being most frequently reported in 6.4% overall and in 6.5% in the elective setting. Stroke was reported in 5.3% of the patients, of which 40% were fatal. The overall perioperative mortality was 3.2%. Median follow-up time was 11 months, and chimney stents remained patent in all patients. CONCLUSIONS TEVAR with the chimney technique is a viable treatment option and may expand treatment strategies for patients with challenging thoracic aortic pathology and anatomy in the emergent and elective setting. Patency of the thoracic chimney stents appears to be good during short-term follow-up. Other complications, such as endoleak and stroke, deserve attention by future research to further improve treatment strategies and the prognosis of these patients.

Oversizing of Aortic Stent Grafts for Abdominal Aneurysm Repair: A Systematic Review of the Benefits and Risks

OBJECTIVE Sizing of aortic endografts is an essential step in successful endovascular treatment of aortic pathology, although consensus regarding the optimal sizing strategy is lacking. Some proximal oversizing is necessary to obtain a seal between the stent graft and the aortic wall and to prevent the graft from migrating, but excessive oversizing might influence the results negatively. In this systematic review, we investigated the current literature to obtain an overview of the risks and benefits of oversizing and to determine the optimal degree of oversizing of stent grafts used for endovascular abdominal aortic aneurysm repair. METHODS PUBMED, EMBASE and Cochrane Library databases were searched for articles related to the impact of proximal endograft oversizing on complications after endovascular aneurysm repair. After in- and exclusion, 23 relevant articles reporting on 8415 patients remained for analysis and critical appraisal. RESULTS Most studies that investigated neck dilatation are flawed by poor methodology. No clear relationship between proximal oversizing and neck dilatation relative to the first post-operative scan was found. None of the studies described a positive relationship between the degree of oversizing and the incidence of endoleaks. On the contrary, oversizing up to 25% seems to decrease the risk of proximal endoleaks. There are conflicting data regarding the risk of graft migration when oversizing by more than 30%. CONCLUSIONS Based on the best available evidence, the current standard of 10-20% oversizing regime appears to be relatively safe and preferable. Oversizing >30% might negatively impact the outcome after EVAR. Studies of higher quality are needed to further assess the relationship between proximal oversizing and the incidence of complications, particularly regarding the impact on aneurysm neck dilatation.

Endograft Collapse after Thoracic Endovascular Aortic Repair

Purpose: To provide insight into the causes, timing, and optimal management of endograft collapse after thoracic endovascular aortic repair (TEVAR). Methods: A comprehensive review was conducted of all published cases of endograft collapse after TEVAR identified using Medline, Cochrane Library Central, and EMBASE. In total, 32 articles describing 60 patients (45 men; mean age 40.6 ±17.2 years, range 17–78) with endograft collapse were included. All data were extracted from the articles and systematically entered into a database for meta-analysis. Results: In the 60 cases of endograft collapse, TEVAR had most commonly been applied to repair traumatic thoracic aortic injuries (39, 65%), followed by acute and chronic type B aortic dissections (9, 15%). The median time interval between TEVAR and diagnosis of endograft collapse was 15 days (range 1 day to 79 months). On average, the collapsed endografts were oversized by 26.7%±12.0% (range 8.3%–60.0%). Excessive oversizing was reported as the primary cause of endograft collapse in 20%, and a small radius of curvature of the aortic arch was responsible for 48% of the cases. The 30-day mortality was 8.3%, and the freedom from procedure-related death at 3 years after diagnosis of stent-graft collapse was 83.1% for asymptomatic patients compared with 72.7% for patients who had symptoms at diagnosis (p=0.029). Conclusion: Endograft collapse typically occurs shortly after TEVAR, most frequently after endovascular repair of traumatic aortic injury. A high level of suspicion for endograft collapse in the first month after TEVAR, as well as further improvement of current endovascular devices, may be required to improve the long-term outcomes of patients after TEVAR.

TEVAR following prior abdominal aortic aneurysm surgery: Increased risk of neurological deficit

OBJECTIVE Evidence regarding the impact of prior abdominal aortic aneurysm (AAA) repair on the risk of neurological deficit after thoracic endovascular aortic aneurysm repair (TEVAR) is lacking. The purpose of this study was to characterize the risk of TEVAR-related neurological deficit in patients who previously underwent infrarenal AAA surgery. METHODS Prospective maintained databases of patients undergoing TEVAR in the participating institutions were searched for patients with a history of prior AAA surgery before TEVAR. Patient and procedural characteristics and postoperative mortality and morbidity were subsequently centrally collected and systematically entered in a database. Univariate and multivariate logistic regression were performed associating variables with postoperative spinal cord ischemia (SCI). RESULTS Seventy-two patients were identified that underwent TEVAR after prior AAA repair. The risk of SCI was 12.5% (n = 9) and significantly higher than the 1.7% risk of SCI in patients without prior AAA repair (relative risk [RR] 7.2, 95% confidence interval [CI] 2.6 to 19.6, P < .0001). Symptoms of SCI completely resolved in 4 patients with prior AAA repair. Univariate analysis demonstrated that the following variables were significant predictors of SCI in patients with prior AAA repair: preoperative renal insufficiency (odds ratio [OR] 29.5; 95% CI 5.3-164, P < .001), increased length of aorta coverage by TEVAR (OR 1.1; 95% CI 1.0-1.2, P .039) and a lengthened time interval between prior AAA repair and TEVAR (OR 1.2; 95% CI 1.0-1.4, P .026). Preoperative renal insufficiency was also significantly associated with the risk of SCI in multivariate analysis (P .011). CONCLUSION Prior infrarenal AAA repair is associated with dramatic increased risk of SCI after TEVAR compared to patients without prior AAA surgery. Preoperative renal insufficiency appears to be an important predictor of SCI after TEVAR in patients with prior AAA repair. A thorough understanding of the risk profile in patients requiring TEVAR following prior AAA surgery is essential when determining appropriate surgical recommendations. If the diameter and rupture risk are large and TEVAR is indicated, the best available care should be offered for maximal protection of the spinal cord in these patients.

The Semmes Weinstein monofilament examination is a significant predictor of the risk of foot ulceration and amputation in patients with diabetes mellitus

OBJECTIVE Diabetic peripheral neuropathy is a major complication of diabetes mellitus (DM) and is the leading cause of foot ulceration and lower extremity amputations (LEAs). The purpose of this systematic review is to evaluate current evidence regarding the prognostic value of the Semmes Weinstein monofilament examination (SWME) in predicting foot ulceration and LEA in patients with DM. METHODS The MEDLINE/PubMed database was searched through November 2009 for articles pertaining to diabetic foot and SWME with no language or publication date restrictions. Prognostic studies with original data assessing the predictive value of SWME for foot ulceration or LEA in patients with DM were included in the selection. Data were systematically extracted and analyzed by two independent investigators. Absolute risks and relative risks were determined for each study. RESULTS Of the 863 studies identified, nine articles were relevant, involving 11,007 patients with DM. Six studies were identified that assessed the prognostic value of SWME regarding diabetic foot ulceration. The relative risk for patients with a positive SWME result versus those with a negative result ranged from 2.5 (95% confidence interval [CI], 2.0 to 3.2) to 7.9 (95% CI, 4.4 to 14.3) in the identified studies with follow up between 1 and 4 years. Three of the studies assessed the risk of LEA with a positive SWME result. The relative risk for LEA ranged from 1.7 (95% CI, 1.1 to 2.6) to 15.1 (95% CI, 4.3 to 52.6) with follow-up between 1.5 and 3.3 years. CONCLUSIONS All nine studies found SWME to be a significant and independent predictor of future foot ulceration or likely of future LEA as well in patients with DM. Therefore, SWME is an important evidence-based tool for predicting the prognosis of patients with diabetic foot, thus enabling improved patient selection for early intervention and management. More research should be conducted to elucidate the relationship between SWME and LEA.

Dissection of the Abdominal Aorta. Current Evidence and Implications for Treatment Strategies: A Review and Meta-Analysis of 92 Patients

Purpose: To report meta-analyses of published clinical experiences with abdominal aortic dissection (AAD), a rare event that is accountable for up to 4% of all aortic dissections. Methods: All English-language articles regarding abdominal aortic dissection were identified using MEDLINE, Cochrane Library Central, and EMBASE databases. All identified articles were critically appraised for relevance and validity before data extraction and the meta-analyses were performed. Original data were identified on 92 AAD patients (62 men; mean age 59±16 years). Results: Of all AADs, 73 (79%) were spontaneous, 13 (14%) traumatic, and 6 (7%) iatrogenic; the majority (68, 74%) were acute presentations. The mean dissection length was 59±16 mm. A pre-existing abdominal aortic aneurysm was present in 39 (42%). Hypertension was more frequently present in patients with spontaneous dissections compared to other dissection types (p=0.001). Concurrent aortic aneurysms were more often associated with spontaneous dissections (p==0.002). Aortic rupture occurred in 9 (10%) AADs. Open surgical repair was performed in 46 (50%), endovascular repair in 19 (21%), and conservative medical treatment in 27 (29%). In-hospital mortality was 4% overall [1 (2%) in the open repair group, 0 endovascular, and 2 (8%) conservative treatment]. Major complications occurred in 9% [6 (13%) in the open repair group, 1 (5%) in the endovascular group, and 1 (4%) in the conservative treatment cohort]. Conclusion: AAD is a rare event that appears to be associated with hypertension and preexisting aneurysmal degeneration of the abdominal aorta. AAD patients are at considerable risk of in-hospital mortality and complications. Endovascular therapy appears to be associated with a relatively low risk of mortality or major complications compared to open repair and conservative treatment.

Mortality after elective abdominal aortic aneurysm repair

Objective:Purpose of this study is to provide detailed age- and gender-specific mortality risks of patients hospitalized for elective AAA repair. Summary Background Data:Whether to perform elective abdominal aortic aneurysm (AAA) surgery is balancing the risks of natural history against the risks of surgical intervention. Literature is lacking mortality risks after elective AAA repair with stratification by both age and gender. Methods:Mortality risks for 28 days, 1 year, and 5 years were derived from a nationwide cohort of patients hospitalized for elective AAA repair in 1997 or 2000. This cohort was formed through linkage of the Hospital Discharge Register with the Dutch Population Register. The relations between demographics, medical history and mortality were studied by Cox regression. Results:A total of 3457 patients were identified; 86% males, mean age 72 ± 8.0 years. Mortality risks after elective AAA repair increased with age: 28-day mortality ranged from 3.3% to 27.1% in men and 3.8% to 54.3% in women, 5-year mortality from 12.9% to 78.1% in men and 24.3% to 91.3% in women. Higher age, congestive heart failure, cerebrovascular disease and diabetes mellitus were independent risk factors for 5-years mortality. Conclusions:Mortality risks after elective AAA repair are strongly age-related. Age, gender, and comorbidities should be taken into account when deciding on surgery. A general threshold of 55 mm for surgery might not be justified for all patients.