Michael L. Marin

Analysis of gender-related differences in lower extremity peripheral arterial disease

INTRODUCTIONnGender-related differences continue to challenge the management of lower extremity (LE) peripheral arterial disease (PAD) in women. We analyzed the time-trends in hospital care of such differences.nnnMETHODSnData for patients with PAD from New York, New Jersey, and Florida state hospital inpatient discharge databases (1998-2007) were analyzed using univariate and multivariate regression analyses.nnnRESULTSnThe 2.4 million PAD-related inpatient discharge records analyzed showed a slight decrease of inpatient procedures for both genders. Compared with men, women had 18% to 27% fewer PAD and 33% to 49% fewer vascular procedural hospitalizations (P < .0001). They were persistently more likely than men to be admitted emergently (56% vs 51% in 1998 and 57% vs 53% in 2007) and discharged to a nursing home. During the study period, the amputation rate declined by 36% in women and 21% in men with PAD, and similarly, open procedures decreased by 36% and 30%. Endovascular procedures, however, increased by 150% in women and 144% in men. Procedural mortality was 4.95% vs 4.37% for men (P < .0001). Female mortality rates were persistently higher after amputations (9.89% vs 8.90%, P < .0001), open (5.49% vs 4.00%, P < .0001), and endovascular procedures (2.87% vs 2.10%, P < .0001). Time trends showed improved mortality for men and women, with a stable difference between the two.nnnCONCLUSIONnThe analysis of representative state administrative databases of inpatient care records demonstrated improvements in mortality and amputation rates over time. However, a gender-related disparity in PAD outcomes remains that merits further investigation.

Midterm results of endovascular stented grafts for the treatment of isolated iliac artery aneurysms

PURPOSEnIsolated aneurysms of the iliac arteries are uncommon lesions that require surgical repair to prevent rupture.nnnMETHODSnDuring a 4-year period, we used endovascular stented grafts (EGs) to treat 28 iliac artery aneurysms that were not associated with aortic aneurysms. Twenty-five patients, with a total of 24 common iliac (15 right, nine left) and four internal iliac (two right, two left) artery aneurysms, underwent endovascular grafting. There were 24 men and 1 woman, with a mean age of 74 years (range, 51 to 88 years). Combined common and internal iliac artery aneurysms were present in three patients. Nineteen patients who underwent treatment with EGs were administered epidural anesthesia (22 epidural, two local, one general). Before surgery, one patient had lower extremity embolization and ischemia from the aneurysm, three had abdominal or back pain, and the remaining were asymptomatic. The EGs were constructed of polytetrafluoroethylene grafts and balloon expandable stents.nnnRESULTSnFour procedure-related complications (12%) occurred (distal extremity embolization, n = 1; wound complications, n = 2; colonic mucosal ischemia, n = 1). Only a minimal reduction in the aneurysmal diameter was seen in 90% of the iliac artery aneurysms treated. The remaining lesions showed no change in size, and no aneurysm had an increase in cross-sectional diameter on computed tomographic images enduring a follow-up period up to 4 years (mean, 24 months). One aneurysm ruptured after successful endovascular exclusion, and the patient underwent treatment with open repair. The 3-year primary patency rate of iliac EGs was 86%.nnnCONCLUSIONnEGs appear to show satisfactory safety and efficacy for the repair of isolated aneurysms of the iliac arteries.

Preoperative Inferior Mesenteric Artery Embolization before Endovascular Aneurysm Repair: Decreased Incidence of Type II Endoleak and Aneurysm Sac Enlargement with 24-month Follow-up

PURPOSEnTo review the effect of preoperative embolization of the inferior mesenteric artery (IMA) before endovascular aneurysm repair (EVAR) on subsequent endoleaks and aneurysm growth.nnnMATERIALS AND METHODSnBetween August 2002 and May 2010, 108 patients underwent IMA embolization before EVAR. Coil embolization was performed in all patients in whom the IMA was successfully visualized and accessed during preoperative conventional angiography. In this cohort, the incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and repeat intervention were compared with a group of 158 consecutive patients with a patent IMA on preoperative computed tomography angiography but not on conventional angiography, who therefore did not undergo preoperative embolization.nnnRESULTSnThe incidence of type II endoleak was significantly higher in patients not treated with embolization (49.4% [78 of 158] vs 34.3% [37 of 108]; P = .015). The incidence of secondary intervention for type II endoleak embolization was also significantly higher in those who did not undergo embolization (7.6% [12 of 158] vs 0.9% [one of 108]; P = .013). At 24 months, an increase in aneurysm sac volume was observed in 47% of patients in the nonembolized cohort (21 of 45), compared with 26% of patients in the embolized cohort (13 of 51; P = .03). No aneurysm ruptures or aneurysm-related deaths were observed in either group. One patient in the embolization group developed mesenteric ischemia and ultimately died.nnnCONCLUSIONSnPreoperative embolization of the IMA was associated with reduced incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and secondary intervention.

An experimental model for the acute and chronic evaluation of intra-aneurysmal pressure.

Purpose: To develop an animal model for the acute and chronic monitoring of pressure within abdominal aortic aneurysms (AAAs) to be treated with endovascular grafts. Methods: A strain-gauge pressure transducer was placed within an AAA created from a prosthetic vascular graft. Prosthetic aneurysms were implanted into 17 canine infrarenal aortas. The intra-aneurysmal pressure was monitored and correlated with noninvasive forelimb sphygmomanometry for 2 weeks. After this time, an intravascular manometer catheter was passed into the aneurysm. Simultaneous pressure measurements were obtained using the implanted strain-gauge pressure transducer, the manometer catheter, and the forelimb sphygmomanometer. Angiography was performed to assess intraluminal morphology, aneurysm anastomoses, and adjoining aortic vessels. In addition, two control animals underwent intra-aneurysmal pressure monitoring after standard surgical aneurysm repair. Results: There was excellent correlation (r = 0.97) between the pressure measurements obtained with the implanted strain-gauge pressure transducer and the intravascular manometer. Close correlation was also observed between the implanted strain-gauge transducer and the forelimb sphygmomanometer (r = 0.88) during postprocedural monitoring. Intra-aneurysmal pressure was lowered dramatically by surgical exclusion (aneurysm: 15/5 ± 7/4 mmHg; systemic: 124/66 ± 34/17 mmHg; p < 0.001). The prosthetic aneurysms were successfully imaged with angiography. Conclusions: This animal model provides an accurate and reproducible means for measuring intra-aneurysmal pressure on an acute and chronic basis. It may be possible to use this model in the assessment of endovascular devices to determine their efficacy in reducing intra-aneurysmal pressure. Evaluation of complications associated with their use, such as patent aneurysm side branches, perigraft channels, and perianastomotic reflux, may also be possible.

The impact of stent graft evolution on the results of endovascular abdominal aortic aneurysm repair

OBJECTIVEnThere have been four eras in the development of endovascular aneurysm repair (EVAR): physician-made grafts, early industry devices, intermediary commercial endografts, and modern stent grafts. This study analyzes differences in outcomes between these four groups and the impact of device evolution and increased physician experience.nnnMETHODSnFrom 1992 to 2012, 1380 patients underwent elective EVAR. Fourteen different devices were used during this time. The four generations were defined as follows: era 1, all physician-made devices; era 2, June 1994 to June 2003; era 3, June 2003 to January 2008; and era 4, January 2008 to July 2012. Grafts used in each era were the following: era 1, physician made; era 2, early industry, such as EVT, Talent, AneuRx, Excluder, Quantum LP, Vanguard, Ancure, and Teramed; era 3, Talent, Endologix, Excluder, AAAdvantage, Zenith, and Aptus; and era 4, Zenith, Endurant, and Excluder.nnnRESULTSnMean age was 75.2 years, and 84.5% were men. Adjunctive procedures decreased from era 1 to era 2 (P < .001) but rose again in eras 3 and 4 (P < .001). Procedure times (P < .001), blood loss (P < .001), and length of stay (P < .001) have decreased in eras 2, 3, and 4 compared with era 1. Major perioperative complications (era 1, 23%; era 2, 5.9%; era 3, 4.9%; and era 4, 4.7%; P < .001), abdominal aortic aneurysm-related perioperative mortality (era 1, 4.3%; era 2, 0.2%; era 3, 0.06%; and era 4, 0.5%; P < .001), and all-cause perioperative mortality (era 1, 7.7%; era 2, 1.9%; era 3, 1.5%; and era 4, 0.47%; P < .001) have also decreased in eras 2, 3, and 4 compared with era 1. Type I and type III endoleaks (P < .001) and the need for reintervention (P < .001) have decreased. Freedom from aneurysm-related mortality has significantly improved.nnnCONCLUSIONSnEVAR has evolved during the last 20 years, resulting in an improvement in efficiency, outcomes, and procedural success. The most significant advance is seen in the transition from era 1 to the later eras.

Fluoroscopically Assisted Thromboembolectomy: An Improved Method for Treating Acute Arterial Occlusions

We performed bilateral femoral artery dissections in a single 50 kg mongrel dog. Digital fluoroscopic arteriograms documented the luminal diameter of the left iliac and right superficial femoral arteries. Balloon thrombectomy catheter passage was performed through hemostatic sheaths by 12 surgeons. Embolectomy balloons were filled with radiographic contrast material and the balloon catheter diameter was compared with the underlying vessel diameter. The percentage of overdistention of the embolectomy balloon relative to the arterial wall was 23%±5% in the iliac artery and 40%±13% in the femoral artery. Over a 25-month period, we used fluoroscopically assisted thromboembolectomy to treat 21 patients with acute arterial or graft occlusions. As the balloon was gently withdrawn to extract intravascular thrombus, deformities of the compliant balloon profile caused by underlying arterial lesions were identified fluoroscopically and their locations recorded to facilitate further treatment. After initial clot removal in these 21 patients, 15 residual lesions were documented. Repeat thrombectomy (n=8), balloon angioplasty (n=3), and placement of intravascular stents (n=4) eliminated all 15 lesions. Luminal continuity was successfully restored in all 21 of these patients, 10 of whom required distal open vascular reconstruction to correct existing outflow artery disease. Fluoroscopically assisted thromboembolectomy is a simple and safe method for treating acute arterial or graft occlusions in patients with diffuse arteriosclerosis. It minimizes arterial damage and blood loss during balloon thrombectomy and reduces the need for intravascular contrast agents. It also has the potential to facilitate accurate identification, localization, and treatment of significant underlying arterial lesions.

Time-resolved MR angiography for the classification of endoleaks after endovascular aneurysm repair.

To evaluate the utility of time‐resolved MR angiography (TR‐MRA), compared with digital subtraction angiography (DSA), in the classification of endoleaks in patients who have undergone endovascular aneurysm repair (EVAR).

A multicenter experience of the management of collapsed thoracic endografts

OBJECTIVESnThoracic endograft collapse after thoracic endovascular aortic repair (TEVAR) is a potentially devastating complication. This study evaluates the management of thoracic stent graft collapse.nnnMETHODSnA multicenter review of thoracic stent graft collapse was performed from 2005 to 2009. Diagnosis and preoperative planning was performed by computed tomography angiography (CTA). Outcome measures included success of endovascular salvage, postoperative complications, and conversion to open repair.nnnRESULTSnEleven patients (10 men) with thoracic endograft collapse were identified. Mean age was 41.2 years old (range, 21-66 years). Indications for the index TEVAR were traumatic aortic transections in 8 patients and acute type B dissections in 3 patients. All were initially treated with the TAG endoprosthesis (Gore and Associates, Flagstaff, Ariz). The median duration from initial repair to diagnosis of collapse was 9 days (range, 1 day-38 months). All collapses were initially treated by endovascular means using another TAG device in 7 patients, a Talent (Medtronic, Santa Rosa, Calif) thoracic stent graft in 3 patients, and a Palmaz (Cordis Endovascular, Warren, NJ) stent in 1 patient. In 1 patient, the secondary TAG did not resolve the collapse and required a Palmaz stent placement. Technical success rate was 91%, while re-expansion of the collapsed endograft was achieved in all patients. Early and late complications were observed in 3 patients. Delayed (>30 days) open conversion with device explantation was performed for an aortoesophageal fistula, physiological aortic coarctation, and prevention of a recurrent collapse in 1 patient each. There were no perioperative deaths or recurrent collapses.nnnCONCLUSIONnEndograft collapse can be successfully managed by endovascular techniques in most cases. Redo-TEVAR using high radial force devices should be considered the initial treatment of choice. Late endograft-related complications after treatment of collapsed endografts are not uncommon and can be safely managed by open conversion.

Evolution of gender-related differences in outcomes from two decades of endovascular aneurysm repair

OBJECTIVEnWomen have been under-represented in trials that set guidelines for the management of aortic aneurysms. Several studies reported inferior outcomes in women compared with men after endovascular aneurysm repair (EVAR). We investigated the relationship between gender and outcomes after EVAR.nnnMETHODSnA total of 1380 consecutive patients underwent elective EVAR from 1992 to 2012. Baseline, intraoperative, and postoperative variables by gender were analyzed from a prospective database.nnnRESULTSnThe cohort comprised 214 women (15.5%) and 1166 men (84.5%). Women were older than men at repair (77.8 vs 74.5 years, P < .001) and had less cardiac disease (P = .005). They had shorter (19.8 ± 12.9 vs 26.3 ± 14.7 mm; P < .001) more angulated aortic necks (38.8° ± 16.1° vs 31.2° ± 14.7°; P < .001) and fewer iliac aneurysms (P = .002). Women had more arterial reconstructions (iliac conduits, P = .006; thrombolysis and thrombectomy, P = .013; patch angioplasty, P < .001; endarterectomy, P < .001), more perioperative complications (16.9% vs 9.1%; P = .001), and more in-hospital days (4.1 vs 3.4 days; P = .029). Perioperative mortality was equivalent (women: 2% vs men: 2.3%; P = .73). Mean follow-up was 30.9 months. Women and men experienced equivalent aneurysm-related deaths and overall survival. Survival curve analysis showed endoleaks were more likely to develop in women than men (P = .005); however, there was no difference in rates of arterial reinterventions required for each gender during the follow-up period.nnnCONCLUSIONSnFemale gender is associated with more periprocedural complications, adjunctive arterial procedures, and increased endoleaks but does not affect long-term reinterventions or survival. Further studies are warranted to elucidate the effect of gender on outcomes. These data should be considered when selecting EVAR for men and women.

Anatomic Risk Factors for Type-2 Endoleak Following EVAR: A Retrospective Review of Preoperative CT Angiography in 326 patients

PurposeWe describe the anatomic characteristics on preoperative CT angiography (CTA) that predispose to type-2 endoleaks after endovascular aneurysm repair (EVAR) for an abdominal aortic aneurysms (AAA).MethodsBetween 1999 and 2010, 326 patients had a CTA before and after EVAR. CTAs were reviewed for maximal sac diameter, >50xa0% circumferential luminal thrombus, and patency of the infrarenal aortic side branches, including the inferior mesenteric artery (IMA) and L2-L5 lumbar arteries. Postoperative CTAs were reviewed for a persistent type-2 endoleak.ResultsOf 326 patients, 30.4xa0% had a type-2 endoleak on CTA. Univariate analysis demonstrated a patent IMA, increased patent individual L2, L3, and L4 lumbar arteries, and an increased number of total patent lumbar arteries in patients with type-2 endoleak compared to those without (pxa0<xa00.001, 0.002, <0.001, <0.001, and <0.001 respectively). Sac diameter, patent L5 lumbar arteries, and >50xa0% circumferential mural thrombus were not significantly different (pxa0=xa00.652, 0.617, and 0.16). Univariate logistic regression demonstrated increased risk of endoleak with each additional patent lumbar artery (odds ratio (OR) 1.26, pxa0<xa00.001). Multivariate analysis of the 326 patients resulted in the delineation of the optimal anatomic variables that predicted a type-2 endoleak: occluded L3 lumbar arteries (OR 0.1, pxa0=xa00.002), occluded L4 lumbar vertebral arteries (OR 0.31, pxa0=xa00.034), and IMA occlusion (OR 0.38, pxa0=xa00.008).ConclusionsUnivariate analysis demonstrated total patent lumbar arteries as a significant predictor of type-2 endoleak. Multivariate analysis demonstrated IMA occlusion, L3 lumbar artery occlusion, and L4 lumbar artery occlusion as independently protective against type-2 endoleak after EVAR.