Timothy Chuter - Academia.edu (original) (raw)

Papers by Timothy Chuter

Annals of Vascular Surgery, 2005

Endovascular aortic aneurysm repair (EVAR) in patients with ectatic iliac arteries is feasible; h... more Endovascular aortic aneurysm repair (EVAR) in patients with ectatic iliac arteries is feasible; however, most studies have reported experience from single institutions where distal flare techniques with endograft components were used on an ''off-label basis.'' The Zenith endovascular graft allows adequate seal in ectatic common iliac arteries (CIAs) with diameters up to 20 mm. To determine whether large or ectatic CIAs are a risk factor for early and late endograft failure, we analyzed data from the Zenith U.S. multicenter trial. Among 352 patients receiving the endograft in the Zenith u.s. clinical study, 156 patients (44%) had at least one ectatic iliac artery (maximum diameter between 14 and 20 mm), whereas 22 (6.3%) had bilateral CIAs of normal diameter (< 14 mm). Variables analyzed included those defined by the reporting standards for EVAR (SVS/AAVS) as well as iliac-related outcome and indications for secondary iliac interventions. Univariate (Kaplan-Meier [KM] receiver operating characteristics curve, and Cox regression analyses were used to determine the association between CIA diameter and iliacrelated complications. The median follow-up period was 24 months. Technical success was similar (>99%) for patients with ectatic and normal CIAs. Only one late type I distal endoleak was reported and was attributed to failure of distal iliac seal in a patient with ectatic CIAs. Freedom from iliac-related secondary intervention (IRSI) was not significantly different between the groups (KM, log-rank test, p = 0.98) with rates at 1, 12, and 24 months of 98%, 97%, and 95% for patients with ectatic CIAs, and 100%, 95%, and 95% for patients with normal iliac arteries, respectively. Moreover, Cox regression analysis revealed that the maximum CIA diameter was not a significant predictor of freedom from IRSI (hazard ratio, 0.98; 95% confidence interval, 0.7-1.4; p = 0.98). In patients with large CIAs, indications for IRSI included distal type I endoleak (1, 0.6%), type III endoleak (1, 0.6%), graft limb occlusion (4, 2.6%), and device stenosis (1, 0.6%). The only IRSI in a patient with normal CIAs was performed for device stenosis (4.6%). In conclusion, the Zenith endograft is effective for EVAR in patients with ectatic CIAs. Moreover, the presence of large CIAs was not associated with an increased risk of adverse iliac-related outcome or subsequent IRSI. Long-term surveillance, however, is mandatory, as IRSIs may be necessary.

Journal of Vascular Surgery, 2014

We conducted our study to describe the incidence, presentation, management, risk factors, and out... more We conducted our study to describe the incidence, presentation, management, risk factors, and outcomes of lower extremity weakness (LEW) after elective endovascular aneurysm repair with multibranched thoracoabdominal stent grafts. Excluding symptomatic patients and those with aortic dissection, between July 2005 and October 2013, 116 patients with aortic aneurysms were treated in a prospective, single-center trial of multibranched endovascular aneurysm repair. LEW that resolved within 30 days of operation was classified as transient. Persistent LEW was defined as inability to walk or stand 30 days after surgery. Perioperative spinal cord protection measures included bypass as needed to maintain flow to the subclavian and internal iliac arteries, cerebrospinal fluid drainage, and permissive hypertension. Postoperative LEW occurred in 24 of 116 patients (20.6%). In 15 (12.9%), LEW was transient with full recovery. Nine patients (7.7%) had persistent LEW, three with paraparesis and six with paraplegia. Five of 24 patients (21%) awoke from anesthesia with LEW. Symptoms of LEW developed within 72 hours of operation in 14 of 24 (58%). Late-onset LEW (≥72 hours postoperatively) always occurred in the presence of a precipitating hypotensive event (5 of 24; 21%). Univariate analysis showed no association between LEW and Crawford type, staged repair, aneurysm extent, or postoperative endoleak. Baseline glomerular filtration rate &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;30 mL/min/1.73 m(2) (odds ratio [OR], 4.2; 95% confidence interval [CI], 1.2-14.6; P = .03), fluoroscopy time &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;190 minutes (OR, 3.6; 95% CI, 1.0-12.7; P = .04), and sustained hypotension (OR, 2.9; 95% CI, 1.1-7.7; P = .04) were identified as independent risk factors for LEW in multivariate analysis. Most episodes of LEW after multibranched endovascular aneurysm repair are transient and do not occur in the operating room. Adjunctive strategies to maintain spinal perfusion, including cerebrospinal fluid drainage and permissive hypertension, may help prevent permanent LEW.

Journal of Vascular Surgery, 2015

We report a case of a 58-year-old patient with a complicated type B aortic dissection who develop... more We report a case of a 58-year-old patient with a complicated type B aortic dissection who developed acute visceral malperfusion after placement of a thoracic aortic stent graft from the true to the false lumen. He underwent an urgent endovascular revision that involved septal fenestration and distal extension of the stent graft into the true lumen.

Journal of Vascular Surgery, 2002

Objective: Endoleaks and endotension are critically important complications of some endovascular ... more Objective: Endoleaks and endotension are critically important complications of some endovascular aortic aneurysm repairs (EVARs). For the resolution of controversial issues and the determination of areas of uncertainty relating to these complications, a conference of 27 interested leaders was held on November 20, 2000. Methods: These 27 participants (21 vascular surgeons, five interventional radiologists, one cardiologist) had previously answered 40 key questions on endoleaks and endotension. At the conference, these 40 questions and participant answers were discussed and in some cases modified to determine points of agreement (consensus), near consensus (prevailing opinion), or disagreement. Results: Conference discussion added two modified questions for a total of 42 key questions for the participants. Interestingly, consensus was reached on the answers to 24 of 42 or 57% of the questions, and near consensus was reached on 14 of 42 or 33% of the questions. Only with the answers to four of 42 or 10% of the questions was there persistent controversy or disagreement. Conclusion: The current endoleak classification system with some important modifications is adequate. Types I and II endoleak occur after 0 to 10% and 10% to 25% of EVARs, respectively. Many (30% to 100%) type II endoleaks will seal and have no detrimental effect, which never or rarely occurs with type I endoleaks. Not all endoleaks can be visualized with any technique, and increased pressure (endotension) can be transmitted through clot. Aneurysm pulsatility after EVAR correlates poorly with endoleaks and endotension. An enlarging aneurysm after EVAR mandates surgical or interventional treatment. These and other conclusions will help to resolve controversy and aid in the management of these vexing complications and should also point the way to future research in this field. (J Vasc Surg 2002;35:1029-35.)

Journal of Vascular Surgery, 2001

Journal of Vascular Surgery, 2007

To assess the effects of magnetic resonance imaging (MRI) on stainless-steel Z-stent-based abdomi... more To assess the effects of magnetic resonance imaging (MRI) on stainless-steel Z-stent-based abdominal aortic prostheses. From June 1996 to December 2005, 550 patients underwent endovascular repair of an infrarenal abdominal aortic aneurysm at a single academic institution by using a stainless-steel Z-stent-based abdominal aortic prosthesis. Routine patient follow-up included computed tomography scans and abdominal plain films at 1, 6, and 12 months after surgery and yearly thereafter. Although patients were specifically instructed not to undergo MRI, retrospective review identified 22 patients (4%) who underwent MRI after stent-graft implantation. Seventeen of 22 patients consented to have their records reviewed as part of this study and underwent MRI at a mean interval of 669 days (range, 3-2179 days) after stent-graft implantation. Eleven patients underwent implantation of Zenith bifurcated stent grafts, and six had custom-made uni-iliac stent grafts. These patients underwent a total of 20 MRI studies-10 of the brain/neck and 10 of the abdomen, pelvis, or spine. In all cases, the magnetic field strength was 1.5 T or less. No patient experienced any symptoms of abdominal or back pain during or after the MRI. Comparison of the pre- and post-MRI computed tomography scans (available in 15 of 17 patients) and abdominal radiographs showed no change in stent-graft structure, position, or function in any of these patients and no increase in abdominal aortic aneurysm diameter in any patient at an average of 899 days after MRI. On the basis of this limited experience, MRI has no discernible effect on the structure, position, or function of stainless-steel Z-stent-based abdominal aortic prostheses.

Journal of Vascular and Interventional Radiology, 1997

Search by Subject Search using Medical Subject Headings ( MeSH), a controlled... more Search by Subject Search using Medical Subject Headings ( MeSH), a controlled vocabulary for indexing life sciences content. Note that some records do not have MeSH. These include Patents and the latest PubMed and PubMed Central records.

The Journal of Thoracic and Cardiovascular Surgery, 2014

Branched endografts are a new option to treat arch aneurysm in high-risk patients. We performed a... more Branched endografts are a new option to treat arch aneurysm in high-risk patients. We performed a retrospective multicenter analysis of all patients with arch aneurysms treated with a new branched endograft designed with 2 inner branches to perfuse the supra aortic trunks. Thirty-eight patients were included. The median age was 71 years (range, 64-74 years). An American Society of Anesthesiologists score of 3 or 4 was reported in 89.5% (95% confidence interval [CI], 79.7-99.3) of patients. The 30-day mortality rate was 13.2% (95% CI, 2.2-24.2). Technical success was obtained in 32 patients (84.2% [95% CI, 72.4-95.9]). Early secondary procedures were performed in 4 patients (10.5% [95% CI, 0.7-20.3]). Early cerebrovascular complications were diagnosed in 6 patients (15.8% [95% CI, 4.0-27.6]), including 4 transient ischemic attacks, 1 stroke, and 1 subarachnoid hemorrhage. The median follow-up was 12 months (range, 6-12 months). During follow-up, no aneurysm-related death was detected. Secondary procedures during follow-up were performed in 3 patients (9.1% [95% CI, 0.0-19.1]), including 1 conversion to open surgery. We compared the first 10 patients (early experience group) with the subsequent 28 patients. Intraoperative complications and secondary procedures were significantly higher in the early experience group. Although not statistically significant, the early mortality was higher in the early experience group (30% [95% CI, 0.0-60.0]) versus the remainder (7.1% [95% CI, 0.0-16.9]; P=.066). Being part of the early experience group and ascending aortic diameter≥38 mm were found to be associated to higher rates of combined early mortality and neurologic complications. Our preliminary study confirms the feasibility and safety of the endovascular repair of arch aneurysms in selected patients who may not have other conventional options. Thoracic IDE NCT00583817, FDA IDE# 000101.

Journal of Endovascular Therapy, 2004

Since the world was first introduced to the concept of endovascular aneurysm repair by Parodi&amp... more Since the world was first introduced to the concept of endovascular aneurysm repair by Parodi&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s landmark procedures in 1990, stent-grafts have assumed a prominent role in the management of abdominal aortic aneurysm. Most modern systems are trackable, accurate, and secure. The resulting endovascular procedure is safe, durable, effective, and versatile. Perhaps the most significant increment in the applicability of the endovascular technique was achieved by the development of bifurcated stent-grafts, which dispensed with inadequate distal aortic implantation sites. Additional branches and fenestrations now permit endovascular repair in cases of thoracoabdominal, pararenal, juxtarenal, and bilateral iliac aneurysms. These advances in device performance have been accompanied by a rapid dissemination of necessary skills, leading to the development of a new superspecialty of vascular therapy, with elements of vascular surgery, interventional radiology, and interventional cardiology.