Stephen M. Hass

Clinical Outcomes for Hostile Versus Favorable Aortic Neck Anatomy in Endovascular Aortic Aneurysm Repair Using Modular Devices

BACKGROUND Endovascular aneurysm repair (EVAR) is not generally recommended for patients with hostile neck anatomy. This study analyzed the clinical implications of various clinical features of proximal aortic neck anatomy. METHODS Prospectively collected data from 258 EVAR patients using modular devices were analyzed. Patients were classified as having favorable neck anatomy (FNA) or hostile neck anatomy (HNA). HNA was defined as any or all of length of <10 mm, angle of >60°, diameter of >28 mm, ≥50% circumferential thrombus, ≥50% calcified neck, and reverse taper. Univariate, multivariate, and Kaplan-Meier analyses were used to compare early and late clinical outcomes. RESULTS FNA was present in 37% and HNA was present in 63%. Clinical and demographic characteristics were comparable. Technical success was 99%. Mean follow-up was 22 months (range, 1-78 months). Perioperative complication rates were 3% for FNA vs 16% for HNA (P = .0027). Perioperative deaths were 0% for FNA and 3% for HNA (P = .2997). Proximal type I early endoleaks (intraoperative) occurred in 9% of FNA vs 22% for HNA (P = .0202). Intraoperative proximal aortic cuffs were used to seal endoleaks in 9% of FNA vs 22% of HNA (P = .0093). At late follow-up, abdominal aortic aneurysm expansion was noted in 6% of FNA vs 7% of HNA (P = .8509). Rates of freedom from late type I endoleaks at 1, 2, 3, and 4 years were 97%, 97%, 97%, and 90% for FNA vs 89%, 89%, 89%, and 89% for HNA (P = .1224); rates for late interventions were 95%, 90%, 90%, and 90% for FNA vs 95%, 93%, 91%, and 85% for HNA (P = .6902). Graft patency at 1, 2, and 3 years was 99%, 99%, and 99% for FNA vs 97%, 92%, and 90% for HNA (P = .0925). The survival rates were 93%, 84%, 76%, and 76% for FNA vs 88%, 82%, 74%, and 66% for HNA (P = .2631). Reverse taper was a significant predictor for early type I endoleak (odds ratio [OR], 5.25, P < .0001), reverse taper (OR, 5.95; P < .0001) and neck length (OR, 4.15; P = .0146) were for aortic cuff use; circumferential thrombus (OR, 2.44; P = .0448), and neck angle (OR, 3.38; P = .009) were for perioperative complications. CONCLUSIONS Patients with HNA can be treated with EVAR, but with higher rates of early (intraoperative) type I endoleak and intervention. The midterm outcomes are similar to FNA.

Vacuum-assisted fascial closure for patients with abdominal trauma.

BACKGROUND Massive fluid resuscitation often is required for patients with intraabdominal trauma. Subsequently, fascial closure is not always possible in this subset of patients. Under these circumstances, an initial step can be the use of a temporary abdominal closure method. The authors currently use a vacuum-assisted closure to manage the open abdomen for some of their trauma patients. They present their experience over the past 3 years. METHODS From January 2000 to December 2002, 48 trauma patients were treated with temporary abdominal closure using a vacuum-assisted dressing. The ultimate management of the abdominal defect, the serum lactate levels measured in the emergency department, and the fluid balance at the last attempt to accomplish fascial closure were reviewed. RESULTS Delayed fascial closure was achieved in 23 (71.9%) of 32 patients who survived to discharge (26 of 48, 54.2%). Of the 32 patients who survived to discharge, 9 (28.1%) required an alternative closure, most often a split-thickness skin graft. Of the 16 patients who died before discharge, 8 died within 24 hours after admission. Whereas 5 of the 16 deaths occurred after delayed abdominal closure, 11 patients died without abdominal closure. Emergency department serum lactate levels above 8 mg/dL show a positive correlation with in-hospital mortality (6 of 16 patients; 38%; p = 0.001) and mortality within 24 hours of admission (6 of 8 patients; 75%; p = 0.003). Admission lactate levels were not associated with the type of closure achieved. However, primary closure was associated with a significant decrease in lactate levels during the first 12 hours. Complications included five abdominal abscesses, two enterocutaneous fistulas, and one split-thickness skin graft failure. CONCLUSIONS Patients requiring temporary abdominal closure have a significant in-hospital mortality rate of 33%. Delayed primary closure with vacuum assistance was achieved for 71.9% of the surviving patients. Maintaining a negative or total positive fluid balance of less than 20 L before the last attempted fascial closure improves successful closure rates, as seen in 19 of 22 patients (86.4%). The vacuum-assisted closure technique also enabled successful primary closure for two patients with extreme delay (>8 days). Elevated serum lactate levels are significantly correlated with early and in-hospital mortality. A significant decrease in lactate level during the first 12 hours is associated with achievement of primary closure.

Prospective randomized trial of routine versus selective shunting in carotid endarterectomy based on stump pressure

BACKGROUND The use of shunting in carotid endarterectomy (CEA) is controversial. This randomized trial compared the results of routine (RS) vs selective shunting (SS) based on stump pressure (SP). METHODS Two-hundred CEA patients under general anesthesia were randomized into RS (98 patients) or SS (102 patients), where shunting was used only if systolic SP (SSP) was <40 mm Hg. Clinical and demographic characteristics were comparable in both groups. Patients underwent immediate and 30-day postoperative duplex ultrasound follow-up. Analysis was by intention-to-treat. RESULTS Of 102 SS patients, 29 (28%) received shunting. Indications for CEA were similar (42% symptomatic for RS; 47% for SS, P = .458). The mean internal carotid artery diameter was comparable (5.5 vs 5.5 mm, P = .685). Mean preoperative ipsilateral and contralateral stenosis was 76% and 38% for RS (P = .268) vs 78% and 40% for SS (P = .528). Mean preoperative ipsilateral and contralateral stenosis was 79% and 56% in the shunted (P = .634) vs 78% and 34% in the nonshunted subgroup of SS patients (P = .002). The mean SSP was 55.9 mm Hg in RS vs 56.2 for SS (P = .915). The mean SSP was 33 mm Hg in the shunted vs 65 in the nonshunted subgroup (P < .0001). Mean clamp time in the nonshunted subgroup of SS was 32 minutes. Mean shunt time was 35 minutes in RS and 33 in SS (P = .354). Mean operative time was 113 minutes for RS and 109 for SS (P = .252), and 111 minutes in shunted and 108 in the nonshunted subgroup (P = .586). Mean arteriotomy length was 4.4 cm for RS and 4.2 for SS (P = .213). Perioperative stroke rate was 0% for RS vs 2% for SS (one major and one minor stroke, both related to carotid thrombosis; P = .498). No patients died perioperatively. Combined perioperative transient ischemic attack (TIA) and stroke rates were 2% in RS vs 2.9% in SS (P > .99). The overall perioperative complication rates were 8.3% in RS (2 TIA, 3 hemorrhage, 1 myocardial infarction [MI], and 1 asymptomatic carotid thrombosis) vs 7.8% in SS (2 strokes, 1 TIA, 3 hemorrhage, 1 MI, and 1 congestive heart failure; P = .917). CONCLUSIONS RS and SS were associated with a low stroke rate. Both methods are acceptable, and surgeons should select the method with which they are more comfortable.

Mesenteric/Celiac Duplex Ultrasound Interpretation Criteria Revisited

BACKGROUND Several published studies with a small sample size have reported differing results of duplex ultrasound (DUS) utilizing different threshold velocities in detecting significant stenosis of superior mesenteric (SMA) or celiac arteries (CA). The present study is based on the largest number of mesenteric duplex/angiography correlations reported to date for the diagnosis of SMA/CA stenosis. METHODS One hundred fifty-three patients (151 SMA and 150 CA) had both DUS and arteriography. Receiver operator curves (ROC) were used to analyze peak systolic velocity (PSV), end diastolic velocity (EDV), and SMA or CA/aortic PSV ratio in detecting ≥50% and ≥70% stenosis. RESULTS For SMA (151 arteries: 84 with ≥50% stenosis [54 of which had ≥70% stenosis] based on angiography): the PSV threshold that provided the highest overall accuracy (OA) for detecting ≥50% SMA stenosis was ≥295 cm/s (sensitivity [sens.] 87%, specificity [spec.] 89%, and OA 88%); and for detecting ≥70% SMA, it was ≥400 cm/s (sens. 72%, spec. 93%, and OA 85%). The EDV threshold that provided the highest OA for detecting ≥50% stenosis was ≥45 cm/s (sens. 79%, spec. 79%, and OA 79%); and for ≥70% stenosis was ≥70 cm/s (sens. 65%, spec. 95%, and OA 84%). ROC analysis showed that PSV was better than EDV and SMA/aortic PSV ratio for ≥50% stenosis of SMA (P = .003 and P = .0005). For celiac arteries (150 arteries: 105 with ≥50% stenosis [62 of which had ≥70% stenosis]): the PSV threshold that provided the highest OA for ≥50% stenosis was ≥240 cm/s (sens. 87, spec. 83%, and OA 86%); and for ≥70% stenosis was ≥320 cm/s (sens. 80%, spec. 89%, and OA 85%). The EDV threshold that provided the highest OA for ≥50% stenosis was ≥40 cm/s (sens. 84%, spec. 48%, and OA 73%); and for ≥70% stenosis was ≥100 cm/s (sens. 58%, spec. 91%, and OA 77%). ROC analysis showed that PSV was better than EDV and SMA/aortic PSV ratio for ≥50% stenosis of CA (P < .0001 and P = .0410.) CONCLUSIONS PSV values can be used in detecting ≥50% and ≥70% SMA/CA stenosis and were better than EDVs and ratios. Previously published data must be validated in individual vascular laboratories. Our results will need prospective validation.

Carotid artery stenting outcomes are equivalent to carotid endarterectomy outcomes for patients with post-carotid endarterectomy stenosis

BACKGROUND Carotid artery stenting (CAS) has been advocated as an alternative to redo surgery for patients with post-carotid endarterectomy (CEA) stenosis. This study compares early and late clinical outcomes for both groups. METHODS This study analyzes 192 patients: 72 had reoperation (Group A) and 120 had CAS for post-CEA stenosis (Group B). Patients were followed prospectively and had duplex ultrasounds at 1 month, and every 6 to 12 months thereafter. The perioperative complications (perioperative stroke, myocardial infarction/death, cranial nerve injury) and 4-year end points were analyzed. A Kaplan-Meier lifetable analysis was used to estimate rates of freedom from stroke, stroke-free survival, ≥50% restenosis, and ≥80% restenosis. RESULTS Demographic/clinical characteristics were comparable for both groups, except for diabetes mellitus and coronary artery disease, which were significantly higher in Group B. The indications for reoperations were transient ischemic attacks/stroke in 72% for Group A versus 57% for Group B (P=.0328). The mean follow-up was 33 months (range, 1-86 months) for Group A and 24 months (range, 1-78 months) for Group B (P=.0026). The proportion of early (<24 months) carotid restenosis prior to intervention was 51% in Group A versus 27% in Group B (P=.0013). The perioperative stroke rates were 3% and 1%, respectively (P=.5573). There were no myocardial infarctions or deaths in either group. The overall incidence of cranial nerve injury was 14% for Group A versus 0% for Group B (P<.0001). However, there was no statistical difference between the groups relating to permanent cranial nerve injury (1% versus 0%). The combined early and late stroke rates for Groups A and B were 3% and 2%, respectively (P=.6347). The stroke-free rates at 1, 2, 3, and 4 years for Groups A and B were 97%, 97%, 97%, and 97% and 98%, 98%, 98%, and 98%, respectively (P=.6490). The stroke-free survival rates were not significantly different. The rates of freedom from ≥50% restenosis at 1, 2, 3, and 4 years were 98%, 95%, 95%, and 95% for Group A versus 95%, 89%, 80%, and 72% for Group B (P=.0175). The freedom from ≥80% restenosis at 1, 2, 3, and 4 years for Groups A and B were 98%, 97%, 97%, and 97% versus 99%, 96%, 92%, and 87%, respectively (P=.2281). Four patients (one symptomatic) in Group B had reintervention for ≥80% restenosis. The rate of freedom from reintervention for Groups A and B were 100%, 100%, 100%, and 100% versus 94%, 89%, 83%, and 79%, respectively (P=.0634). CONCLUSIONS CAS is as safe as redo CEA. Redo CEA has a higher incidence of transient cranial nerve injury; however, CAS has a higher incidence of ≥50% in-stent restenosis.

Predictors of percutaneous access failure requiring open femoral surgical conversion during endovascular aortic aneurysm repair

OBJECTIVE To determine predictors of percutaneous (PEVAR) access failure requiring conversion to an open approach (OEVAR) during endovascular aortic aneurysm repair (EVAR). METHODS A single-center retrospective review of all EVAR patients from January 2009 through June 2011 with multivariate analysis of clinical and anatomic variables that could impact access outcome was conducted. Target vessel calcification was categorized as mild, moderate, or severe based on circumferential calcium arc (<⅓, ⅓ to ½, and >½ respectively), dyslipidemia (defined as low-density lipoprotein >130 mg/dL or receiving lipid lowering medication), and obesity (defined as body mass index [BMI] >30). RESULTS We investigated 400 access sites for 200 patients who underwent EVAR. The study cohorts characteristics included an average age of 72.8 ± 9.0 years, vessel size of 9.6 ± 1.8 mm, sheath size of 17.1 ± 3.0 Fr, BMI of 27.6 ± 5.3, and estimated glomular filtration rate of 68.5 ± 24.2 mL/min. Comorbidities included dyslipidemia in 129 patients (64.5%) and diabetes in 54 patients (27%). There were 132 OEVAR (66 patients), two mixed OEVAR with contralateral PEVAR (one patient), and 266 (133 patients) PEVAR approaches. Use of PEVAR increased over time (45.5% [2009], 77.8% [2010], and up to 88.5% [2011]; P = .001) while conversions decreased (24.3% [2009], 8.7% [2010], and 4.3% [2011]; P = .001]. More OEVAR patients (35.8%) stayed longer than 3 days compared with 21.1% for PEVAR (P = .028). For the 266 PEVAR approaches, 32 access sites (12.0%) had to be converted. Severely calcified arteries were most predictive of conversion (odds ratio [OR], 36.4; P < .001). Year of procedure (2010; OR, 0.17; P = .001; 2011, OR, 0.20; P = .049), female gender (OR, 3.1; P = .017), moderately calcified arteries (OR, 2.5; P = .085), and age (OR, 2.3 [per decade]; P = .002) were all also significant. Vessel size, sheath size, and BMI were found to be nonsignificant predictors of conversion. CONCLUSIONS PEVAR was found to be safe, reliable, and feasible. Several factors, including learning curve, vessel calcification, age, and female gender predicted conversion of PEVAR to OEVAR.

The relationship of preoperative thrombus load and location to the development of type II endoleak and sac regression.

BACKGROUND Few studies have specifically correlated the amount of thrombus in the aneurysm sac and the presence of type II endoleaks (TIIE). This study examined the correlation of preoperative thrombus load and location to the incidence of TIIE and late sac regression. METHODS Prospectively collected data from 266 endovascular aneurysm repair (EVAR) patients were analyzed. Maximum thrombus thickness (MTT) and percentage of the circumference of the aortic wall lined by thrombus (thrombus-lined aneurysm circumference [TLAC]) were determined from preoperative computed tomography angiography (CTA) images at four levels: neck, maximum abdominal aortic aneurysms (AAA) diameter (zone B), zone A (between neck and zone B), and zone C (between zone B and aortic bifurcation). The number of aortic side branches (ASB) was also recorded (inferior mesenteric artery [IMA], accessory renals, lumbar, and middle sacral). Logistic regression was used to determine the association of TIIE with each variable. RESULTS Thirty-three (12%) early and 32 (13%) late TIIE were noted at a mean follow-up of 22 months (range, 1-87 months). The mean MTT at zone B was 19.7 mm in patients without early TIIE and 18.8 mm in patients without late TIIE vs 14.4 and 17.2 mm in patients with early and late TIIE (P = .0137 and P = .444, respectively). The mean percentage of TLAC was 76% and 75% vs 65% and 64% in patients without vs with early and late TIIE (P = .0329 and P = .044, respectively). There was no correlation of early and late TIIE and thrombus location by zones. The IMA was patent in 7% and 7% of patients without early and late TIIE vs 16% and 15% with TIIE (P = .0367 and P = .077, respectively). The mean number of ASB in patients without (early and late) TIIE was 5.8 and 5.6 vs 5.8 and 7 with endoleak (P = .932 and P = .001, respectively). Univariate analysis showed the following variables decreased the incidence of early TIIE: MTT for zone B (odds ratio [OR] 0.79 for 5-mm increase; P = .014), MTT zone A (OR, 0.78; P = .028), MTT zone C (OR, 0.82; P = .043), and percentage of TLAC (OR, 0.88 for 10% increase; P = .036). For late TIIE: percentage of TLAC (OR, 0.88 for 10% increase; P = .048), and ASB (OR, 1.39 for each additional vessel; P = .001). A multiple regression model showed only ASB (OR, 1.34; P = .009) was a predictor for late TIIE. Four of five patients (80%) with late sac expansion vs 24 of 208 (12%) without expansion had late TIIE (P = .001). CONCLUSIONS MTT, percentage of TLAC, number of ASB, and patent IMA influenced early TIIE; however, only the number of ASB influenced late TIIE.

Critical analysis of renal duplex ultrasound parameters in detecting significant renal artery stenosis.

BACKGROUND Several published studies have reported differing results of renal duplex ultrasound (RDU) imaging in detecting significant renal artery stenosis (RAS) using different Doppler parameters. This study is the largest to date to compare RDU imaging vs angiography and assess various published Doppler criteria. METHODS RDU imaging and angiography were both done in 313 patients (606 renal arteries). RAS was classified as normal, <60%, ≥ 60% to 99%, and occlusion. Main outcome measurements included renal peak systolic velocity (PSV), systolic renal-to-aortic ratio (RAR), end-diastolic velocity (EDV), and kidney lengths. RESULTS The mean PSVs and RARs for normal, <60%, and ≥ 60% stenosis were 173, 236, and 324 cm/s (P < .0001), and 2.2, 2.9, and 4.5, respectively (P < .0001). The PSV cutoff value that provided the best overall accuracy for ≥ 60% stenosis was 285 cm/s, with a sensitivity, specificity, and overall accuracy of 67%, 90%, and 81%, respectively. The RAR cutoff value with the best overall accuracy for ≥ 60% stenosis was 3.7, with a sensitivity, specificity, and overall accuracy of 69%, 91%, and 82%, respectively. A PSV of ≥ 180 cm/s and RAR of ≥ 3.5 had a sensitivity, specificity, and overall accuracy of 72%, 81%, and 78% in detecting ≥ 60% stenosis. A PSV of ≥ 200 cm/s with an RAR of ≥ 3.5 had a sensitivity, specificity, and overall accuracy of 72%, 83%, and 78% in detecting ≥ 60% stenosis. A receiver operator characteristic (ROC) curve analysis showed that the PSV and RAR were better than the EDV in detecting ≥ 60% stenosis: PSV area under the curve (AUC) was 0.85 (95% confidence interval [CI], 0.81-0.88), EDV AUC was 0.71, and RAR AUC was 0.82 (PSV vs EDV, P < .0001; PSV vs RAR, P = .075; EDV vs RAR, P < .0001). A PSV of 285 cm/s or RAR of 3.7 alone were better than any combination of PSVs, EDVs, or RARs in detecting ≥ 60% stenosis. The mean kidney length was 10.4 cm in patients with ≥ 60% stenosis vs 11.0 cm in patients with <60% stenosis (P < .0001). Twelve percent of patients with ≥ 60% stenosis had a kidney length of ≤ 8.5 cm vs 4% in patients with <60% stenosis (P = .0003), and 5.6% (34 of 606) had accessory renal arteries on angiography, with six detected on RDU imaging. The presence of accessory renal arteries, solitary kidneys, or renal fibromuscular dysplasia had no influence on overall accuracy of using PSV values for detecting ≥ 60% stenosis. CONCLUSIONS A PSV of 285 cm/s or an RAR of 3.7 alone can be used in detecting ≥ 60% RAS. Previously published data must be validated in individual vascular laboratories.

Perioperative and late clinical outcomes of percutaneous transluminal stentings of the celiac and superior mesenteric arteries over the past decade

BACKGROUND Several authorities have proposed stenting of the superior mesenteric artery (SMA)/celiac artery (CA) as the primary treatment for patients with chronic mesenteric ischemia. However, most of these reports had small samples and short follow-up periods. METHODS Eighty-three patients were treated over a 10-year period. Clinical follow-up and duplex ultrasound exams were done to evaluate long-term patency. We used our newly validated duplex criteria to detect ≥70% in-stent stenosis of the SMA and CA. A Kaplan-Meier life-table analysis was used to estimate freedom from in-stent stenosis and late symptom and survival rates. RESULTS Fifty-four SMA and 51 CA stents were analyzed. The initial technical and clinical success rates were 97% and 96%, respectively, with 2% procedure morbidity and 2% mortality. The primary late clinical success rate was 59%, and the late ≥70% in-stent stenosis rate was 51% at a mean follow-up of 31 months (range, 1-124). Freedom from late recurrent symptoms at 1, 2, 3, 4, and 5 years was 83, 77, 70, 70, and 65%, respectively. Survival rates at the same intervals were 88%, 82%, 70%, 64%, and 51%. Primary patency rates for the whole series were 69%, 48%, 39%, 28%, and 19% at 1, 2, 3, 4, and 5 years, respectively. Assisted primary patency rates for the whole series were 80%, 61%, 54%, 43%, and 34% at 1, 2, 3, 4, and 5 years, respectively. Primary patency rates for the SMA at 1, 2, 3, 4, and 5 years were 71%, 47%, 37%, 28%, and 18%, respectively; and assisted primary rates were 82%, 64%, 57%, 45%, and 32%, respectively. Primary patency rates for the CA were 68%, 50%, 40%, 29%, and 21%; and assisted primary rates were 79%, 58%, 52%, 42%, and 36% for 1, 2, 3, 4, and 5 years, respectively. There were no significant differences in either primary or assisted primary patency between the SMA and CA (P = .7729 and .8169). A secondary intervention was carried out in 30% of the series. Freedom from ≥70% in-stent stenosis for the SMA was 82%, 65%, 56%, 42%, and 34%, and that for the CA was 73%, 59%, 48%, 34%, and 25%, at 1, 2, 3, 4, and 5 years, respectively. CONCLUSIONS Stenting of SMA/CA stenosis has high technical/early clinical success rates with a satisfactory late clinical outcome; however, it is associated with high rates of late in-stent stenosis and intervention.

Evolving treatment of popliteal artery aneurysms

BACKGROUND Over the past decade, the treatment of popliteal aneurysms has evolved at our institution from sole operative intervention during the initial part of the study period, to combined surgical and endovascular treatment, and finally to endovascular-centered management in more recent years. METHODS This is a retrospective review of all patients with popliteal aneurysms treated at our institution from 2001 to 2011. Data collection included the indication for intervention, treatment details, interventional patency, limb salvage, perioperative outcome, and midterm survival. RESULTS Eighty-eight aneurysms (72 patients) were treated during this period. Indications for intervention included symptomatic presentations in 53% (n = 47) and asymptomatic in 47% (n = 41). Treatment included endovascular exclusion in 24, surgical repair in 63 (14 posterior approach and 49 medial approach with bypass and exclusion), and primary amputation in one patient. Nine aneurysms (10.2%) received catheter-directed thrombolysis. Demographics were similar between the two treatment cohorts, except for age with endovascular stenting patients being significantly older (76.0 vs 66.0 years; P = .002). The mean length of stay was 3.9 days vs 9.5 days (P < .001), favoring endovascular treatment. There were no perioperative (30-day) deaths in the endovascular group and one in the surgical cohort. The mean patency follow-up was 21.2 vs 28.3 months. Primary patency did not differ between endovascular and surgically treated patients at 1 year (92.9% vs 83.3%; P = .26) and 3 years (63.7% vs 77.8%; P = .93). No limbs were lost in the endovascular group during the follow-up period of 22.4 months, and one late limb loss occurred in the surgical cohort (mean follow-up, 29.2 months). Endovascular patients had a midterm survival rate of 65% (mean follow-up, 33.9 months), whereas surgical patients experienced a survival rate of 80.8% (mean follow-up, 42.9 months; P = .22). CONCLUSIONS Endovascular treatment of popliteal aneurysms provides similar short-term patency to that of the traditional gold standard approach with surgical bypass, with shorter hospitalizations in both symptomatic and asymptomatic patients. Further long-term follow-up is required to compare these two treatment modalities for durability to determine the optimal popliteal aneurysm management.