Mark D. Morasch

Safety of gadolinium contrast angiography in patients with chronic renal insufficiency

OBJECTIVE To prevent iodinated contrast medium-induced nephrotoxicity, gadolinium has been used increasingly for magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA) to visualize arterial anatomy in patients undergoing vascular surgery who are considered at high risk because of chronic renal insufficiency. We assessed the safety of gadolinium-based contrast medium as a substitute for iodinated contrast medium-enhanced examinations. We determined the incidence of gadolinium-induced nephrotoxicity in a clinical setting and searched for contributing risk factors. Patients and methods In a single-center retrospective study from December 1999 to January 2001, 218 inpatients underwent MRA and 42 inpatients underwent DSA, with gadolinium as the sole contrast agent. Patient comorbid conditions, indications for vascular imaging, contrast dose, urine output, baseline and post-procedure serum creatinine concentration (SCr), and outcome were recorded for all patients in whom gadolinium-induced renal failure developed. RESULTS Of 260 patients who received gadolinium-based contrast agents, at a dose of 0.25 mmol/kg or more, 195 patients (75%) had pre-test baseline chronic renal insufficiency. In 7 of 195 patients (3.5%) acute renal failure developed after gadolinium-based contrast medium administration, for MRA (n = 153) in 3 patients (1.9%) and DSA (n = 42) in 4 patients (9.5%). Average baseline SCr in the 195 patients with chronic renal insufficiency was 38.2 +/- 1.6 mL/min/1.73 m(2), and in the 7 patients in whom acute renal failure developed, baseline SCr was 32.5 +/- 7.8 mL/min/1.73 m(2) (P =.33). Respective intravenous and intra-arterial gadolinium doses in these 7 patients ranged from 0.31 to 0.41 mmol/kg for MRA and 0.27 to 0.42 mmol/kg for DSA. Acute renal failure did not develop in any of 65 patients with normal baseline SCr. CONCLUSION Despite reports of negligible nephrotoxicity, rarely gadolinium-based contrast agents can cause acute renal failure in patients with underlying chronic renal insufficiency. Estimation of creatinine clearance alone does not enable prediction of which patients are likely to have acute renal failure. Patients at high-risk should be identified, and prophylactic measures should be taken to reduce the risk for nephrotoxicity.

Transthoracic repair of innominate and common carotid artery disease: Immediate and long-term outcome for 100 consecutive surgical reconstructions

PURPOSE This is a review of 100 consecutive supraaortic trunk reconstructions (SAT) performed over 16 years. METHODS There were eight innominate endarterectomies and 92 bypass procedures based on the thoracic aorta (n = 86) or proximal innominate artery (n = 6) in 98 patients 24 to 79 years of age. Indications included cerebrovascular ischemia in 83 and upper extremity ischemia in four. Thirteen patients were asymptomatic. An innominate lesion was bypassed in 78 cases. The left common carotid and left subclavian arteries required reconstruction in 38 and nine patients, respectively. Multiple trunks were reconstructed by direct bypass grafting in 35. Approach was via median sternotomy in 92, partial sternotomy in six, and left thoracotomy in two. Seven patients underwent concomitant cardiac surgery. RESULTS Eight deaths and eight nonfatal strokes occurred, for a combined stroke/death rate of 16%. The operative mortality rate was 6% for SAT and 29% for SAT/cardiac operations. Perioperative complications included two asymptomatic graft occlusions, three nonfatal myocardial infarctions, seven significant pulmonary complications, three sternal wound infections, and one recurrent laryngeal nerve injury. Follow-up ranged from 1 to 184 months (mean, 51 +/- 4.8 months). Eight patients were lost to follow-up. Twenty-one late deaths occurred. Two SATs required late revision. The cumulative primary patency rates at 5 and 10 years were 94% +/- 3% and 88% +/- 6%, respectively. The stroke-free survival rates at 5 and 10 years were 87% +/- 4% and 81% +/- 7%, respectively. Patients who survived beyond 30 days had a median stroke-free life expectancy of 10 years, 7 months (SE, 6%). CONCLUSIONS Direct reconstruction of complex symptomatic SAT lesions can be performed with acceptable death/stroke rates and with long-term patient benefit. Asymptomatic lesions in patients who have significant concomitant conditions should be managed with a less-morbid cervical or endovascular approach, even if long-term outcome of the latter is inferior.

Arterial reconstruction with cryopreserved human allografts in the setting of infection: A single-center experience with midterm follow-up

OBJECTIVES Vascular reconstruction in the setting of primary arterial or prosthetic graft infection is associated with significant morbidity and mortality. Cryopreserved human allografts (CHA) may serve as acceptable alternatives when autogenous or extra-anatomic/in situ prosthetic reconstructions are not possible. METHODS Between February 1999 and June 2008, 57 CHAs were placed in 52 patients (average age, 65 years) for abdominal aortic (n = 18) or iliofemoral/femoral-popliteal arterial or prosthetic infections (n = 39). Indications for arterial reconstruction included infected implanted prosthetic material (n = 39), mycotic pseudoaneurysms (n = 14), or intra-abdominal bacterial contamination or wound infection (n = 4). Wide local debridement and culture was followed by allograft interposition, bypass, or extra-anatomic reconstruction. Over a similar time period, 53 non-CHA extra-anatomical prosthetic or in situ autogenous tissue reconstructions were performed in 53 patients (average age, 65 years) for abdominal aortic (n = 18) or iliofemoral and femoral-popliteal (n = 35) prosthetic graft infections. Indications for arterial replacement in all cases included infected implanted prosthetic material. RESULTS Thirty-day mortality for all CHA and non-CHA reconstructions was 5.2% and 7.5%, respectively. The 1-year procedure-related mortality for all CHA and non-CHA procedures was 7.0% and 13.2%, respectively. In the CHA cohort, 5 patients required re-exploration for hemorrhage or anastomotic disruption. In midterm CHA follow-up (20 months), there was 1 graft thrombosis, 2 graft stenoses, 1 recurrent ilioenteric fistula, and 1 non-related amputation. The remainder of the CHA reconstructions remained patent without evidence of aneurysmal change or reinfection. CONCLUSION In the setting of infection, cryopreserved human allograft arterial reconstruction is a viable alternative to traditional methods of vascular reconstruction in patients without available autogenous conduit and when expedient reconstruction is required. In midterm follow-up, cryopreserved allografts appear to be resistant to subsequent reinfection, thrombosis, or aneurysmal dilatation. However, larger patient populations and longer follow-up are needed to determine if arterial reconstruction with CHA is the safest and most durable method of treatment for arterial infections.

A review of 100 consecutive reconstructions of the distal vertebral artery for embolic and hemodynamic disease

PURPOSE The aim of our study was to assess the outcome of distal vertebral artery (VA) reconstructions through a retrospective review conducted at a university-affiliated referral center. METHODS One hundred consecutive distal VA reconstructions had been performed during a period of 14 years (98 patients) and included reversed saphenous vein bypass from the ipsilateral common, internal, or external carotid to the third portion of the VA at the C1-2 level (68 reconstructions) or the C0-1 level (4); transposition of the external carotid or its occipital branch to the VA (23); and transposition of the third portion of the VA onto the internal carotid artery (2). Other methods were used in 3 additional patients. Eighteen patients underwent concomitant carotid operations, and 1 patient underwent a concomitant subclavian transposition. Symptoms were present in 98% of patients and included vertebrobasilar ischemia (89%), vertebrobasilar plus hemispheric ischemia (7%), and hemispheric ischemia (2%). Two asymptomatic patients with bilateral carotid occlusions underwent operations to provide a single artery for cerebral perfusion (2%). Sixty-three lesions were atherosclerotic, 18 were dynamic bony compressions, and 14 were dissection, fibromuscular dysplasia, arteritis, or aneurysm. Five had miscellaneous anatomic indications. RESULTS Stroke caused the four perioperative deaths that occurred. There was one occurrence of nonfatal hemispheric stroke. Routine postoperative arteriography identified 16 graft abnormalities; 11 patients underwent attempted revision. The introduction of the use of intraoperative angiography in 1990, halfway through the series, lowered the incidence of graft abnormalities from 28% to 4% and the incidence of perioperative death from 6% to 2%. Eighty-seven percent of patients had complete or significant resolution of symptoms. Follow-up ranged from 1 to 168 months (mean, 79 months). Ten patients were lost to follow-up. Twenty late deaths occurred; none were stroke related. Five reconstructions required late revision. The cumulative primary patency at 5 and 10 years was 75% +/- 6 and 70% +/- 7 (mean +/- SE), respectively; cumulative secondary patency was 84% +/- 5 and 80% +/- 6 at 5 and 10 years, respectively. Median survival was 107 months. CONCLUSIONS Distal VA reconstruction provides excellent long-term patency and stroke protection. Intraoperative angiography is mandatory.

Secondary infections of thoracic and abdominal aortic endografts.

PURPOSE To review several cases of stent-graft infection with respective outcomes to identify clinical presentations and responses to treatment options. MATERIALS AND METHODS The authors performed a single-center retrospective review of all secondary endograft infections from January 2000 to June 2007. Infections were identified from an institutional database containing all abdominal and thoracic endovascular aneurysm repairs (EVAR and TEVAR) performed at the treating hospital. RESULTS From January 2000 to June 2007, 389 EVAR and 105 TEVAR were performed at the treating hospital. Ten endograft infections were identified (five EVAR and five TEVAR). Four infections occurred in grafts placed at outside institutions and six in grafts placed in-house. The in-house prevalence of EVAR and TEVAR infection is 0.26% and 4.77%, respectively. None were placed for a presumed pre-existing mycotic aneurysm. The mean time from the index procedure to the diagnosis of infection was 243.6 days +/- 74.5. Two patients who underwent EVAR presented with a contained rupture, and the remaining eight patients presented with constitutional symptoms and/or abscess formation on imaging studies. Microbiology cultures revealed Propionibacterium species (n = 3), Staphylcoccus species (n = 3), Streptococcus species (n = 2), and Enterobacter cloacae (n = 1). All EVAR patients underwent removal of the infected endograft and reconstruction with extraanatomic bypass (n = 3) or in situ homograft placement (n = 2). During a mean follow-up of more than 1 year, there were no recognized complications or recurrence of infection. Only one of the five TEVAR patients underwent removal and interposition grafting with an antibiotic-impregnated Dacron graft. The remaining four patients were medically managed--one patient survived and was placed in hospice care, two died of mycotic aneurysm rupture, and one died from multiorgan system failure secondary to sepsis. CONCLUSIONS Graft-related septic complications following EVAR or TEVAR are rare but associated with significant mortality. Several surgical treatment options are available, each potentially equally successful. The effect of prophylactic antibiotic use during subsequent invasive procedures must be solidified.

Treatment and outcomes of aortic endograft infection

OBJECTIVE This study examined the medical and surgical management and outcomes of patients with aortic endograft infection after abdominal endovascular aortic repair (EVAR) or thoracic endovascular aortic repair (TEVAR). METHODS Patients diagnosed with infected aortic endografts after EVAR/TEVAR between January 1, 2004, and January 1, 2014, were reviewed using a standardized, multi-institutional database. Demographic, comorbidity, medical management, surgical, and outcomes data were included. RESULTS An aortic endograft infection was diagnosed in 206 patients (EVAR, n = 180; TEVAR, n = 26) at a mean 22 months after implant. Clinical findings at presentation included pain (66%), fever/chills (66%), and aortic fistula (27%). Ultimately, 197 patients underwent surgical management after a mean of 153 days. In situ aortic replacement was performed in 186 patients (90%) using cryopreserved allograft in 54, neoaortoiliac system in 21, prosthetic in 111 (83% soaked in antibiotic), and 11 patients underwent axillary-(bi)femoral bypass. Graft cultures were primarily polymicrobial (35%) and gram-positive (22%). Mean hospital length of stay was 23 days, with perioperative 30-day morbidity of 35% and mortality of 11%. Of the nine patients managed only medically, four of five TEVAR patients died after mean of 56 days and two of four EVAR patients died; both deaths were graft-related (mean follow-up, 4 months). Nineteen replacement grafts were explanted after a mean of 540 days and were most commonly associated with prosthetic graft material not soaked in antibiotic and extra-anatomic bypass. Mean follow-up was 21 months, with life-table survival of 70%, 65%, 61%, 56%, and 51% at 1, 2, 3, 4, and 5 years, respectively. CONCLUSIONS Aortic endograft infection can be eradicated by excision and in situ or extra-anatomic replacement but is often associated with early postoperative morbidity and mortality and occasionally with a need for late removal for reinfection. Prosthetic graft replacement after explanation is associated with higher reinfection and graft-related complications and decreased survival compared with autogenous reconstruction.

The use of cryopreserved aortoiliac allograft for aortic reconstruction in the United States

BACKGROUND Aortic infections, even with treatment, have a high mortality and risk of recurrent infection and limb loss. Cryopreserved aortoiliac allograft (CAA) has been proposed for aortic reconstruction to improve outcomes in this high-risk population. METHODS A multicenter study using a standardized database was performed at 14 of the 20 highest volume institutions that used CAA for aortic reconstruction in the setting of infection or those at high risk for prosthetic graft infection. RESULTS Two hundred twenty patients (mean age, 65; male:female, 1.6/1) were treated since 2002 for culture positive aortic graft infection (60%), culture negative aortic graft infection (16%), enteric fistula/erosion (15%), infected pseudoaneurysm adjacent to the aortic graft (4%), and other (4%). Intraop cultures indicated infection in 66%. Distal anastomosis was to the femoral artery and iliac. Mean hospital length of stay was 24 days, and 30-day mortality was 9%. Complications occurred in 24% and included persistent sepsis (n = 17), CAA thrombosis (n = 9), CAA rupture (n = 8), recurrent CAA/aortic infection (n = 8), CAA pseudoaneurysm (n = 6), recurrence of aortoenteric fistula (n = 4), and compartment syndrome (n = 1). Patients with full graft excision had significantly better outcomes. Ten (5%) patients required allograft explant. Mean follow-up was 30 ± 3 months. Freedom from graft-related complications, graft explant, and limb loss was 80%, 88%, and 97%, respectively, at 5 years. Primary graft patency was 97% at 5 years, and patient survival was 75% at 1 year and 51% at 5 years. CONCLUSIONS This largest study of CAA indicates that CAA allows aortic reconstruction in the setting of infection or those at high risk for infection with lower early and long-term morbidity and mortality than other previously reported treatment options. Repair with CAA is associated with low rates of aneurysm formation, recurrent infection, aortic blowout, and limb loss. We believe that CAA should be considered a first line treatment of aortic infections.

Multislice dark-blood carotid artery wall imaging: A 1.5 T and 3.0 T comparison†

To compare two multislice turbo spin‐echo (TSE) carotid artery wall imaging techniques at 1.5 T and 3.0 T, and to investigate the feasibility of higher spatial resolution carotid artery wall imaging at 3.0 T.

Long-term sac behavior after endovascular abdominal aortic aneurysm repair with the Excluder low-permeability endoprosthesis

PURPOSE Sac regression is a surrogate marker for clinical success in endovascular aneurysm repair (EVAR) and has been shown to be device-specific. The low porosity Excluder endograft (Excluder low-permeability endoprosthesis [ELPE]; W. L. Gore & Associates Inc, Flagstaff, Ariz) introduced in 2004 was reported in early follow-up to be associated with sac regression rates similar to other endografts, unlike the original Excluder which suffered from sac growth secondary to fluid accumulation in the sac. The purpose of this study was to determine whether this behavior is durable in mid-term to long-term follow-up. METHODS Between July 2004 and December 2007, 301 patients underwent EVAR of an abdominal aortic aneurysm (AAA) with the ELPE at two institutions. Baseline sac size was measured by computed tomography (CT) scan at 1 month after repair. Follow-up beyond 1 year was either with a CT or ultrasound scan. Changes in sac size ≥5 mm from baseline were determined to be significant. Endoleak history was assessed with respect to sac behavior using χ(2) and logistic regression analysis. RESULTS Two hundred sixteen patients (mean age 73.6 years and 76% men) had at least 1-year follow-up imaging available for analysis. Mean follow-up was 2.6 years (range, 1-5 years). The average minor-axis diameter was 52 mm at baseline. The proportion of patients with sac regression was similar during the study period: 58%, 66%, 60%, 59%, and 63% at 1 to 5 years, respectively. The proportion of patients with sac growth increased over time to 14.8% at 4-year follow-up. The probability of freedom from sac growth at 4 years was 82.4%. Eighty patients (37.7%) had an endoleak detected at some time during follow-up with 29.6% (16 of 54) residual endoleak rate at 4 years; 13 of the residual 16 endoleaks were type II. All patients with sac growth had endoleaks at some time during the study compared with only 18% of patients with sac regression (P < .0001). CONCLUSION A sustained sac regression after AAA exclusion with ELPE is noted up to 5-year follow-up. Sac enlargement was observed only in the setting of a current or previous endoleak, with no cases of suspected hygroma formation noted.

A comparative study of the bell-bottom technique vs hypogastric exclusion for the treatment of aneurysmal extension to the iliac bifurcation

INTRODUCTION A significant proportion of patients undergoing endovascular aneurysm repair (EVAR) have common iliac artery aneurysms (CIAA). Aneurysmal involvement at the iliac bifurcation potentially undermines long-term durability. METHODS Patients with CIAA who underwent EVAR were identified in two teaching hospitals. Bell-bottom technique (BBT; iliac limb ≥20 mm) or internal iliac artery embolization and limb extension to the external iliac artery (IIE + EE) were used. Outcome between these two approaches was compared. RESULTS We identified 185 patients. Indication for EVAR included asymptomatic abdominal aortic aneurysm (AAA) in 157, symptomatic or ruptured aneurysm in 19, and CIAA in nine. Mean AAA diameter was 59 mm. Among 260 large CIAAs that were treated, BBT was used to treat 166 CIAA limbs, and 94 limbs underwent IIE + EE. Total reintervention rates were 11% for BBT (n = 19) and 19.1% for IIE + EE (n = 18; P = .149). Rates of reintervention for type Ib or III endoleak were 4% for BBT (n = 7) and 4% for IIE + EE (n = 4; P > .99). The difference in limb patency rates was not significant. The 30-day mortality rate was 1%. Median follow-up was 22 months. Complications did not differ significantly between the two groups; however, the combined incidence of perioperative complications and reinterventions was higher in the IIE + EE group (49% vs 22%; P = .002). CONCLUSIONS The combined incidence of perioperative complications and reinterventions is significantly higher with IIE + EE than with BBT; therefore, when feasible, BBT is desirable.