Double-barrel stenting for endovascular repair of a superior mesenteric artery dissecting aneurysm

The patient was a 58-year-old man with a history of hypertension who had incidentally been found to have a 2.7-cm dissecting fusiform superior mesenteric artery aneurysm involving a long segment of a proximal to distal superior mesenteric artery. Double-lumen anatomy was present, with the true lumen perfusing the proximal and mid-small bowel and the false lumen perfusing the distal small bowel and the ileocolic artery. The patient elected to undergo endovascular repair using double-barrel stenting with self-expanding and balloon-expandable covered stents, as described. Computed tomography angiography after 1 year demonstrated patent stents.

Duplex Ultrasound Can Successfully Identify Endoleaks and Renovisceral Stent Patency in Patients Undergoing Complex Endovascular Aneurysm Repair

Efficacy of duplex ultrasound (DU) surveillance of complex EVAR such as FEVAR and ChEVAR has not been studied. All patients undergoing FEVAR or ChEVAR at a single multihospital institution were retrospectively reviewed. Postoperative surveillance included DU at 1 month and CTA at 3 months. 82 patients met inclusion criteria including 39 (47.6%) ChEVAR and 43 (52.4%) FEVAR cases. DU identified endoleak with aneurysm sac enlargement in 3 cases requiring reintervention. CTA at 3 months detected 2 new endoleaks without growth and 1 renal artery stent occlusion. Replacement of initial postoperative imaging with DU did not result in any missed endoleaks, deaths, ruptures, or branch occlusions.

Shockwave lithotripsy facilitates large-bore vascular access through calcified arteries

Background

Our objective is to explore the Peripheral Intravascular Lithotripsy (IVL) System in the treatment of calcific access vessels during thoracic endovascular aortic repair (TEVAR), endovascular aortic repair (EVAR), and transcatheter aortic valve intervention.

Methods

This retrospective, single-center study evaluated the outcomes of patients undergoing TEVAR, EVAR, or transcatheter aortic valve intervention with severe calcific arterial disease between July 2018 and August 2019. Maximum circumferential calcification, length of calcification, and inner/outer diameter measurements were collected with curved planar reformation by medical imaging software (Aquarius APS, TeraRecon, Foster City, Calif). Effective luminal gain was calculated using the minimal inner diameter and the largest bore passed within the vessel lumen. End points included technical success, mortality, adverse events, and requirement for bail out maneuvers. Technical success was defined as successful delivery and deployment of device or endograft.

Results

Nine patients were included (mean age, 79.3 ± 9.79 years; range, 59-97 years]). four transcatheter aortic valve replacement, one TEVAR, one EVAR, and three fenestrated EVAR. Six patients (66.7%) had more than one artery treated; the segments treated included common iliac artery (seven patients [77.8%]), the external iliac artery (seven patients [77.8%]), and the common femoral artery (one patient [11.1%]). The average inner iliac vessel diameter was 3.38 ± 0.99 mm (range, 1.87-4.72 mm). The average outside diameter of device introduced was 7.2 ± 0.94 (range, 6.3-8.8 mm) with 229% effective luminal gain. Technical success was achieved in 100% of cases with a 0% mortality. Adjunctive measures were needed in five cases (55.6%). One vessel perforation was controlled with covered stent (Viabahn; W. L. Gore & Associates, Flagstaff, Ariz) deployment. Dissection was identified in two cases requiring stent placement. Two cases required the use of the Terumo International Systems SOLOPATH Balloon Expandable TransFemoral System (Terumo Interventional Systems, Somerset, NJ). One case deployed a Viabahn stent applying the "crack and pave" technique.

Conclusions

As the population of the United States ages, calcified arterial disease will become an everyday clinical conundrum. Furthermore, the procedures for which the IVL system is geared toward facilitating will likely also increase in use. The IVL system is an additional tool in the vascular surgeon's armamentarium to obtain large-bore access in these calcified vessels. Further studies are needed to better assess the clinical effectiveness of the IVL system.

Two-year evaluation of fenestrated and parallel branch endografts for the treatment of juxtarenal, suprarenal, and thoracoabdominal aneurysms at a single institution

OBJECTIVE

Despite numerous recent pivotal and small-scale trials, real-world endovascular management of juxtarenal aneurysms (JRA), suprarenal aneurysms (SRA), and thoracoabdominal aortic aneurysms (TAAA) remains challenging without consensus best practices. This study evaluated the mortality, graft patency, renal function, complication, and reintervention rates for fenestrated and parallel endografts in complex aortic aneurysms repairs.

METHODS

This retrospective review of consecutive included patients with JRA, SRA, or TAAA who underwent complex endovascular repair from August 2014 to March 2017 at one high-volume institution. Treatment modality was a single surgeon decision based on patients anatomy and the urgency of the repair. Patient demographics, hospital course, and follow-up visits inclusive of imaging were analyzed. Ruptured aneurysms were excluded. Survival rates and outcomes were determined using the Kaplan-Meier method with log-rank tests.

RESULTS

Seventy complex endovascular aortic repairs were performed; 38 patients with TAAA were treated with snorkel/sandwich parallel endografts (21 celiac, 28 superior mesenteric arteries, 58 renal arteries) and 32 patients with JRA/SRA were treated by fenestrated endovascular aneurysm repair (FEVAR) with 94 total fenestrations (2 celiac, 30 SMA, 62 renal). The mean patient age was 74.8 ± 10.0 years. Sixty percent were male, and the mean aortic aneurysm diameter was 6.0 ± 1.4 cm. Perioperative mortality was 3.1% (1/32) for FEVAR compared with 2.6% (1/38) for parallel endografts (P = .9). All-cause reintervention rates were 15.6% in FEVAR (5/32) vs 23.6% with parallel endografts (9/38; P = .4). Branch reintervention rates per each branch endograft were 4.3% for FEVAR (4/94; 2 renal stent occlusions, 1 colonic ischemia without technical issue found on reintervention, 1 perinephric hematoma) vs 3.7% for parallel endografts (4/107; 2 renal and 1 celiac stent thromboses, and 1 renal stent kink; P = .41). The endograft branch thrombosis rate was 2.1% in FEVAR (2/94) vs 2.7% in parallel endografts (3/109; P = .77). Reinterventions owing to endoleaks were performed in five patients (2 type I, 2 type III, and 1 gutter endoleak; 13.1%) with parallel grafts vs no endoleak reinterventions in FEVAR. The overall survival and freedom from aneurysm-related mortality at 24 months was 78% and 96.9% in FEVAR vs 73% and 93.4% for parallel endografts (P = .8 and P = .6). The median follow-up was 12 months (range, 1-32 months).

CONCLUSIONS

Parallel and fenestrated endografts have acceptable and comparable mortality and patency rates in endovascular treatment of JRA, SRA, and TAAA. This study reaffirms that parallel endografts are a safe and viable alternative to fenestrated devices for complex aortic aneurysmal disease despite often treating more urgent patients and more complicated anatomy unable to be treated with FEVAR.

The Epidemiology, Pathophysiology, and Novel Treatment of Calcific Arterial Disease

Endovascular treatment of arterial diseases has become first-line in most cases due to improved technology. However, until recently, excessive atherosclerotic calcification has been a major limiting factor in the endovascular management of peripheral arterial disease, as well as vascular access for endovascular aneurysm repair (EVAR) and transcatheter aortic valve replacement (TAVR). The Peripheral Intravascular Lithotripsy (IVL) System (Shockwave Medical, Inc., Fremont California) applies pulsatile mechanical energy under fluoroscopic guidance to disrupt calcified lesions. The purpose of this paper is to introduce IVL in the treatment of calcific access vessels in preparation for EVAR and TAVR, as well as peripheral arterial disease applications to enhance luminal gain. Using the IVL System, angioplasty can be performed with lower pressures, which may minimize arterial dissection. Further, the lithotripsy effect on calcium will enhance vessel compliance. We describe several cases where IVL was applied successfully and present additional cases that may have benefitted from the use of this technology.

Pulse Wave Imaging in Carotid Artery Stenosis Human Patients in Vivo

Carotid stenosis involves narrowing of the lumen in the carotid artery potentially leading to a stroke, which is the third leading cause of death in the United States. Several recent investigations have found that plaque structure and composition may represent a more direct biomarker of plaque rupture risk compared with the degree of stenosis. In this study, pulse wave imaging was applied in 111 (n = 11, N = 13 plaques) patients diagnosed with moderate (>50%) to severe (>80%) carotid artery stenosis to investigate the feasibility of characterizing plaque properties based on the pulse wave-induced arterial wall dynamics captured by pulse wave imaging. Five (n = 5 patients, N = 20 measurements) healthy volunteers were also imaged as a control group. Both conventional and high-frame-rate plane wave radiofrequency imaging sequences were used to generate piecewise maps of the pulse wave velocity (PWV) at a single depth along stenotic carotid segments, as well as intra-plaque PWV mapping at multiple depths. Intra-plaque cumulative displacement and strain maps were also calculated for each plaque region. The Bramwell-Hill equation was used to estimate the compliance of the plaque regions based on the PWV and diameter. Qualitatively, wave convergence, elevated PWV and decreased cumulative displacement around and/or within regions of atherosclerotic plaque were observed and may serve as biomarkers for plaque characterization. Intra-plaque mapping revealed the potential to capture wave reflections between calcified inclusions and differentiate stable (i.e., calcified) from vulnerable (i.e., lipid) plaque components based on the intra-plaque PWV and cumulative strain. Quantitatively, one-way analysis of variance indicated that the pulse wave-induced cumulative strain was significantly lower (p < 0.01) in the moderately and severely calcified plaques compared with the normal controls. As expected, compliance was also significantly lower in the severely calcified plaques regions compared with the normal controls (p < 0.01). The results from this pilot study indicated the potential of pulse wave imaging coupled with strain imaging to differentiate plaques of varying stiffness, location and composition. Such findings may serve as valuable information to compensate for the limitations of currently used methods for the assessment of stroke risk.

One-Year Outcomes Following Directional Atherectomy of Popliteal Artery Lesions: Subgroup Analysis of the Prospective, Multicenter DEFINITIVE LE Trial

Purpose: To report the effectiveness of directional atherectomy for the treatment of popliteal artery occlusive disease. Methods: This subset of the prospective, multicenter, single-arm DEFINITIVE LE trial included 158 patients (mean age 72.0±10.9 years; 82 men) who underwent directional atherectomy in 162 popliteal artery lesions between 2009 and 2011. Forty-eight (30.4%) patients were suffering from critical limb ischemia (CLI). The mean lesion length was 5.8±3.9 cm; 38 (23.5%) arteries were occluded. The primary outcome measure for patients with intermittent claudication (IC) was duplex ultrasound–defined primary patency at 1 year; the outcome for subjects with CLI was freedom from major amputation of the target limb at 1 year. Outcomes and adverse events were independently assessed. Results: Procedure success (≤30% residual stenosis) was achieved in 84.4% of treated lesions; adjunctive stenting was required in 6 (3.7%) of the 162 lesions. The 1-year primary patency rate was 75.0% (IC patients 78.2% and CLI patients 67.5%, p=0.118). The freedom from major amputation in both cohorts was 100%. In both IC and CLI patients, significant improvements were demonstrated at 1 year in the Rutherford category, walking distance, and quality of life in comparison to baseline. Conclusion: This study indicates that directional atherectomy in popliteal arteries leads to favorable technical and clinical results at 1 year for claudicant as well as CLI patients.

Hybrid Repair Techniques for Complex Aneurysms and Dissections Involving the Aortic Arch and Thoracic Aorta

Aortic aneurysms involving the ascending aorta, aortic arch, and descending thoracic aorta have been a challenging entity to surgically treat for over 60 years. Despite the mortality of the disease, early open surgical procedures also had significant morbidity and mortality. The inherent risk in treating multiple anatomic segments simultaneously led to the innovation of the staged elephant trunk (ET) approach by Borst in 1983. To avoid the thoracotomy and associated complications related to the second stage of the procedure, an endovascular completion paradigm was begun by Volodos in 1991. This theoretical hybrid technique combinined shorter and less elaborate open supra-aortic trunk debranching with less invasive endovascular exclusion and has grown since then in terms of different approaches and case volume. The rise of thoracic endovascular aortic repair (TEVAR) combined with debranching bypass has allowed certain lesions to be treated without a large scale intrathoracic open surgical procedure. The complexity and extensiveness of certain lesions, however, has necessitated a hybrid approach such as the frozen elephant trunk (FET) and the standard ET with second stage TEVAR. The former has been used to treat multifocal degenerative aneurysms, chronic dissections with aneurysm, and acute extensive dissections. After conventional proximal aortic replacement, a stent-graft (SG) is delivered antegrade through the transected arch where it is sutured proximally and then "frozen" distally via endovascular means. The FET has the advantage of avoiding a second stage, but potentially introduces a greater rate of spinal cord ischemia compared to the standard elephant trunk. Improvements on the FET procedure have included the development of more advanced hybrid SG such as the Vascutek® Thoraflex™ Hybrid graft (Vascutek Ltd, Scotland, UK), which consists of a distal en,dograft sealed to a proximal four-branched Vascutek Gelweave™ Vascutek Ltd, Scotland, UK) and incorporated sewing collar. While open surgery continues to be a component of complex aortic arch aneurysms, the development of hybrid devices that can bridge the gap between open and endovascular surgery will continue to flourish.

Endovascular Solutions to Complications of Open Aortic Repair

Open repair of abdominal aortic aneurysms (AAAs) or occlusive disease can be complicated by pseudoaneurysm formation and aneurysmal dilatation of native vessels. Reports of reoperation for these new lesions have a mortality rate of 5–17% electively, and 24–88% if ruptured. These complications are commonly several years after initial repair, and progression of other comorbidities can further complicate a repeat exploration. The authors reviewed 5 cases of late complications of open aortic bypass surgery treated with endovascular stent grafting as an alternative to reexploration in patients with increased risk for morbidity and mortality. Over a 6-year experience, 5 patients underwent endovascular stent grafting to repair paraanastomotic aneurysms. Patient records were reviewed and clinical cardiac risk evaluation was performed. Follow-up clinic notes and computed tomography (CT) scans were evaluated. Between October 1996 and February 2002, 5 patients underwent 6 endovascular procedures to repair paraanastomotic aneurysms. Mean period between interventions was 16.6 ±6.27 years (range 10–25); mean age at endovascular procedure 74.2 ±6.37 years (range 67–84). Cardiac clinical risk index increased in 80% of patients by Goldman Risk Index and in 40% by the Modified Cardiac Risk Index. On completion angiography, there was complete exclusion of the paraanastomotic aneurysms in all cases (100%). Length of postoperative stay was 1.5 ±0.547 days. Mean estimated blood loss at conclusion of endovascular procedure was 577 ±546.504 cc (range, 60 cc–1,500 cc). Mean follow-up was 24.4 ±24.593 months (range, 5–67 months). On repeat imaging, all stent grafts remain patent without rupture or endoleak. Endovascular stent grafting to repair late complications of open AAA repair is a viable alternative to reexploration in patients with significant comorbidities. These procedures can be performed without violating the previous surgical planes of sites. The operations can be performed under local anesthesia and with reduced hospitalizations. In patients with increased risk factors, endovascular stent grafting is a less morbid alternative to open surgical techniques.

Prophylactic Interruption of the Inferior Vena Cava: Immediate and Long-Term Results

To determine the effects of prophylactic interruption of the inferior vena cava (IVC) the hospital course of 340 patients who underwent aortic operations with placement of a Moretz IVC clip between 1980 and 1988 was removed: 175 patients had had abdominal aortic aneurysm resection; 143, aortobifemoral by pass; and 22, aortobiiliac endarterectomy or bypass. There were no complica tions related to placement of the IVC clip. After operation, any clinical suspicion of deep vein thrombosis (DVT) or pulmonary embolus (PE) was docu mented by phlebography or pulmonary arteriography, respectively. In the im mediate postoperative period ( < thirty days), only 2 (0.5%) patients had a PE and 10 (2.9%) a DVT. For long-term follow-up extending to eight years (mean ± 42.8 months), 308 patients were available. During long-term follow-up, 2 (0.6%) patients had a PE and 7 (2.2%) a DVT. Limb edema without evidence of DVT occurred in another 7 (2.2%) patients. B-mode ultrasonography of the IVC was performed in 163 patients. The IVC was clearly patent in all but 5 (3%): 1 had had a documented PE in the immediate postoperative period, and the other 4, an asymptomatic occlusion of the IVC during late follow-up.

Prophylactic IVC interruption in aortic surgical patients appears not to cause IVC thrombosis, to initiate DVT, or to cause chronic venous insufficiency. The results indicate that it is a safe method of decreasing the incidence of PE, without increasing operative morbidity.

Ruptured Abdominal Aortic Aneurysm: Factors Affecting Survival and Long-Term Results

Although elective resection of an abdominal aortic aneurysm (AAA) is now a safe operation, the mortality related to a ruptured abdominal aortic aneurysm (rAAA) remains significant. To evaluate factors affecting survival and the long- term results after rAAA, a ten-year review of 47 patients was performed.

The operative mortality rate was 43% (20/47) compared with 2.6% for 147 elective AAA patients during this period. Factors adversely affecting survival were blood pressure <90 mmHg on arrival to the hospital, perioperative cardiac arrest, delay in time from diagnosis to treatment > six hours, age > seventy-five years, massive transfusion, and free intraperitoneal rupture.

In follow-up extending to five years the survivors of rAAA at one (92%) and five (53%) years had no discernible differences in quality of life or long- term survival compared with age- and sex-matched patients who had elective AAA resection during the same time interval.

When an rAAA occurs and any three of the adverse variables noted above are present, the mortality rate exceeds 90%. These patients remained ventilator dependent and in the ICU from one to sixty-seven days, accumulating hospital charges from $7,000 to $214,000. It appears that the most effective means of reducing mortality statistics in this inordinately low-salvage, yet high-cost sub group of patients, is to prevent rupture of an AAA by elective resection.

Ischemic Colitis Following Ruptured Abdominal Aortic Aneurysm

During a six-year period, 47 patients underwent operation for ruptured abdominal aortic aneurysm (rAAA) with a mortality rate of 38% (18/47): of the 39 patients surviving the initial surgery, 9 (23%) developed ischemic colitis. All 9 patients demonstrated hyperdynamic cardiovascular changes consistent with sepsis: decreased systemic vascular resistance (SVR) (mean 852 dynes/sec/cm2) and increased cardiac index (mean 3.8 L/min/m2). This "septic picture" in the postoperative period, before the onset of any gastrointestinal (GI) symptoms (diarrhea with/without blood), led the authors to question bowel viability. Flexible sigmoid colonoscopy identified ischemic colitis in all patients and sigmoid colectomy was performed in 4; 3 of these patients survived. Of the 5 remaining patients managed nonoperatively, 3 survived. When hyperdynamic cardiovascular changes were recognized "early" (< forty-eight hours) and ischemic colitis was diagnosed (5 patients), all patients survived. However, when ischemic colitis was diagnosed "late" (> forty-eight hours) after operation in 4 patients, only 1 (25%) survived.

In patients who suffer an rAAA and demonstrate cardiodynamic signs of sepsis (especially falling SVR) in the immediate postoperative period (< forty-eight hours), immediate bedside sigmoid colonoscopy to rule out ischemic colitis is warranted. Similarly, when patients develop "late" cardiodynamic signs of sepsis during recuperation from rAAA, even before the onset of GI symptoms, sigmoid colonoscopy should be performed. If severe ischemic colitis is documented, aggressive management with frequent colonoscopy and possibly sigmoid resection is indicated, for this may offer the only chance of survival in these catastrophically ill patients.

Relationship Between Preoperative Duplex Vein Mapping and Intraoperative Longitudinal Impedance in Infrainguinal Vein Grafts

The importance of favorable vein size, resistance, and impedance for the sustained success of infrainguinal vein grafting procedures has repeatedly been demonstrated. Estimating these properties preoperatively, however, has been problematic. Ultrasonic vein mapping is a reliable technique for measuring vein diameters at venous pressures, but it is unknown whether these data accurately assess the resistive potential of the conduit in the arterial circulation. The purpose of this study was to compare vein diameter measured preoperatively with vein graft longitudinal impedance measured intraoperatively.

Patients who had undergone both preoperative vein mapping and intraoperative impedance studies at the time of infrainguinal bypass were included (December 1995-April 1999). Vein mapping was performed using B-mode ultrasound with a 10 MHz probe. The dimensions of the specific vein segment used for reconstruction were tabulated and its mean diameter (D̄) was calculated. At the time of operation, following reconstruction, transgraft blood pressure gradient (δP) and blood flow (Q) waveforms were recorded by using digital data acquisition. Longitudinal impedance (ZL) was calculated as δP/Q at each harmonic following Fourier transformation and the area under the curve from 0 to 4 Hz designated as ∫ZL.

Twenty-three bypasses in 22 patients were studied (D̄ = 3.5 ±0.2 mm, range 1.6-5.5 mm; ∫ZL= 37 ±4 x 103 dyne cm-5, range 13-95 X 103 dyne cm-5). D̄ significantly correlated with ∫ZL (slope = -0.454, p < 0.05), albeit with a fairly low correlation coefficient ( r2 = 0.23). D̄ > 3.6 mm was predictive of graft patency at 12 months (D̄ > 3.6 mm 100% vs D̄ < 3.6 mm 57 ±20%; p = 0.02).

Larger veins identified by preoperative mapping have, in general, more favorable intraoperative resistive characteristics as defined by a lower JZL. However, some veins thought to have small diameters (< 3.6 mm) may still demonstrate sufficiently low ∫ZL when grafted to remain patent.