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Biomedical subjects

George E Kopchok

Publications and source records attributed to George E Kopchok.

10 recordsLinked to original sources
PubMed2006

Endograft exclusion of acute and chronic descending thoracic aortic dissections.

OBJECTIVES: To analyze the results of endograft exclusion of acute and chronic descending thoracic aortic dissections (Stanford type B) with the AneuRx (n = 5) and Talent (n = 37) thoracic devices and to compare postoperative outcomes of endograft placement acutely (<2 weeks) and for chronic interventions. METHODS: Patients treated for acute or chronic thoracic aortic dissections (Stanford type B) with endografts were included in this study. All patients (n = 42) were enrolled in investigational device exemption protocols from August 1999 to March 2005. Three-dimensional computed tomography reconstructions were analyzed for quantitative volume regression of the false lumen and changes in the true lumen over time (complete >95%, partial >30%). RESULTS: Forty-two patients, all of whom had American Society of Anesthesiologists (ASA) risk stratification > or =III and 71% with ASA > or = IV, were treated for Stanford type B dissections (acute = 25, chronic = 17), with 42 primary and 18 secondary procedures. All proximal entry sites were identified intraoperatively by intravascular ultrasound (IVUS). The procedural stroke rate was 6.7% (4/60), with three posterior circulation strokes. Procedural mortality was 6.7% (4/60). The left subclavian artery was occluded in 11 patients (26%) with no complaints of arm ischemia, but there was an association with posterior circulation strokes (2/11) (18%). No postoperative paraplegia was observed after primary or secondary intervention. Complete thrombosis of the false lumen at the level of endograft coverage occurred in 25 (61%) of 41 patients < or =1 month and 15 (88%) of 17 patients at 12 months. Volume regression of the false lumen was 66.4% (acute) and 91.9% (chronic) at 6 months. Lack of true lumen volume (contrast) increase and increasing false lumen volume (contrast) suggests continued false lumen pressurization and the need for secondary reintervention. Thirteen patients (31%) required 18 secondary interventions for proximal endoleaks in 6, junctional leaks in 3, continued perfusion of the false lumen from distal re-entry sites in 3, and surgical conversion in 4 for retrograde dissection. CONCLUSIONS: Preliminary experience with endografts to treat acute and chronic dissections is associated with a reduced risk of paraplegia and lower mortality compared with open surgical treatment, the results of medical treatment alone, or a combination.

Acute Disease↗
PubMed2006

Intravascular ultrasound use in the treatment of thoracoabdominal dissections, aneurysms, and transections.

Intravascular ultrasound (IVUS) has become an important adjunct in the endovascular treatment of thoracoabdominal aortic pathology. In this article, we hope to describe and define the expanding role of IVUS as a tool for the vascular surgeon in the treatment of thoracoabdominal aortic dissections, aneurysms, and transections. IVUS is of particular benefit in the treatment of aortic dissections and aortic transections.

Aortic Dissection↗
PubMed2006

Principles and devices.

The development of catheter-based ultrasound imaging began in the 1950s using large-diameter catheters and frequencies of between 1 and 10 MHz. In the 1970s, 360 degrees cross-sectional imaging of vessels was reported using multi-element or phase-array transducers. Since then, refinements in imaging frequency, catheter size, image quality, and computer-driven imaging platforms have transformed intravascular ultrasound (IVUS) from predominantly a research tool to an important clinical intervention.

Cardiac Catheterization↗
PubMed2004

Endovascular abdominal aortic aneurysm repair using the AneuRx stent graft: impact of excluding accessory renal arteries.

The aim of this study was to evaluate clinical sequelae of accessory renal artery exclusion during endo-AAA repair. Medical records and pre- and postoperative CT scans were reviewed from 114 AAA patients treated with the AneuRx stent graft between 1996-2001. Thirty-seven accessory renal arteries were identified in 32/114 patients (28%) with 19/32 patients having infrarenally located accessory renal arteries. In group I (11 patients), the stent graft excluded 11 accessory renal arteries. In group II (8 patients), eight accessory renal arteries were not excluded. Average infrarenal neck length was 24.9 mm in group I vs. 30.7 mm in group II (p = 0.07). The average length of device seal was similar in both groups (19.4 vs. 18.5 mm, p = 0.67). There were no perioperative deaths, significant postoperative hypertension, rise in serum creatinine, or postoperative renal infarctions in either group. Three of eight patients (38%) in the non-excluded group developed type I proximal endoleaks whereas none in the excluded patient group did (p = 0.06). Accessory renal arteries may be safely excluded during endovascular AAA repair and may result in a more secure proximal device fixation.

Aged↗
PubMed2003

Cardiac risk stratification in patients undergoing endoluminal graft repair of abdominal aortic aneurysm: a single-institution experience with 365 patients.

OBJECTIVE: Patients undergoing abdominal aortic aneurysm repair have a high incidence of coexisting cardiac disease. The traditional cardiac risk stratification for open abdominal aortic aneurysm surgery may not apply to patients undergoing endoluminal graft exclusion. The purpose of this study was to examine predictive risk factors for perioperative cardiac events. METHODS: As part of multiple prospective endograft trials approved by the US Food and Drug Administration, data for 365 patients who underwent endoluminal graft repair from 1996 to 2001 were collected. Variables included for analysis were age and sex; history of smoking; presence of hypertension, diabetes mellitus, or renal insufficiency; Eagle clinical cardiac risk factors; American Society of Anesthesiologists index; type of anesthesia administered; estimated blood loss; preoperative hemoglobin level; preoperative use of beta-blocker therapy; duration of surgery; need for iliac artery conduit; and concomitant other vascular procedures. Univariate and multivariate logistic regression analysis were used to determine which variables were predictive of an adverse perioperative cardiac event, eg, Q wave and non-Q wave myocardial infarction (MI), congestive heart failure (CHF), severe arrhythmia, and unstable angina. RESULTS: The study cohort included 322 men and 43 women (mean age, 74.2 years). Fifty-two (14.2%) postoperative cardiac events occurred: severe dysrhythmia in 15 patients (4.1%), MI in 14 patients (3.8%), non-Q wave MI in 8 patients (2.2%), CHF in 8 patients (2.2%), and unstable angina in 7 patients (1.9%). Univariate analysis demonstrated that age 70 years or older (P =.034), history of MI (P =.018), angina (P =.004), history of CHF (P <.001), two or more Eagle risk factors (P <.001), and lack of use of preoperative beta-blocker therapy (P =.005) were predictors of perioperative cardiac events. Multivariate analysis identified only age 70 years or older (P =.026), history of MI (P =.024) or CHF (P =.001), and lack of use of preoperative beta-blocker therapy (P =.007) as independent risk factors for an adverse cardiac event. CONCLUSIONS: Age 70 years or older, history of MI or CHF, and lack of use of preoperative beta-blocker therapy are independent risk factors for perioperative cardiac events in patients undergoing endoluminal graft repair.

Adrenergic beta-Antagonists↗
PubMed2003

Volume regression of abdominal aortic aneurysms and its relation to successful endoluminal exclusion.

OBJECTIVES: Evaluating the success of endoluminal repair of abdominal aortic aneurysms (AAAs) is frequently based on diameter measurements and determining the presence of endoleaks. The use of three-dimensional volumetric data and observation of morphologic changes in the aneurysm and device have been proposed to be more appropriate for postdeployment surveillance. The purpose of this study was to analyze the long-term volumetric and morphologic data of 161 patients who underwent endovascular AAA exclusion and to assess the utility of volume measurements for determining successful AAA repair. METHODS: Patients with spiral computed tomography scans obtained preoperatively, within the first postoperative month, at 6 months, and annually thereafter, were included in this analysis. Computerized interactive three-dimensional reconstruction of each AAA scan was performed. Total aneurysm sac volume was measured at each time interval (mean preoperative volume 169.0 +/- 78.5 mL), and the significance of volume changes was determined by mixed linear modeling, a form of repeated measures analysis, to account for longitudinal data clustered at the individual level. Sixty-two patients (38%) developed endoleaks at some time during follow-up-15 type I leaks, 45 type II leaks, and 2 type III leaks. The patients with type I and type III leaks were treated with cuffs, and the type II leaks were treated either with observation, side-branch embolization, or required open conversion. RESULTS: Aneurysm sac volume increased slightly at 1-month follow-up (+3.3%), and then decreased steadily to -12.9% at 5 years (P <.0001). This effect remained unchanged after controlling for the three device types used in our study population. Patients who did not exhibit an endoleak (n = 99) showed a significant decrease in aneurysm volume across the entire follow-up duration when compared with those who did exhibit an endoleak (n = 62) (P <.0001). The presence of a 10% or greater decrease in volume at 6 months demonstrated a sensitivity of 64%, a specificity of 95%, a positive predictive value of 95%, a negative predictive value of 62%, and an accuracy of 75% for predicting primary clinical success defined by successful deployment of the device; freedom from aneurysm- or procedure-related death; freedom from endoleak, rupture, migration, or device malfunction; or conversion to open repair. CONCLUSIONS: Volumetric analysis may be used to predict successful endoluminal exclusion of AAAs. Volume regression appears to be device-independent and should be expected in most clinically successful cases. The presence of volume increases in the first 6 months is suspicious for an endoleak that is pressurizing the aneurysm sac and heralds the need for closer evaluation and possible intervention. A volume decrease of 10% or greater at 6 months and continuing regression over time is associated with successful endovascular repair.

Aged↗
PubMed2002

Endovascular exclusion of abdominal aortic pathology in patients with concomitant malignancy.

The advent of endoluminal aortic repair has gained increasing popularity as an alternative to traditional open surgery in the setting of multiple comorbid disease states. This study analyzes a single center experience of excluding aortic disease in patients with concomitant malignancy. As part of a Federal Drug Administration FDA-approved trial, 318 patients underwent aortic stent-graft repair between June 1996 and February 2001. During that period five patients with advanced-stage neoplasia were treated. Endovascular management of symptomatic abdominal aortic aneurysms (AAA) with a mean diameter of 7.8 cm (range, 6-10 cm), was performed in four patients. In the fifth patient, a custom-made aortic prosthesis was utilized to exclude a paraanastamotic abdominal aneurysm (PAAA) from a previous open AAA repair. Malignancies included esophageal, lung, renal, prostate, and urinary bladder cancers. A mean follow-up of 10.1 months was available. Successful endoluminal repair was accomplished in all five patients with minimal in-hospital morbidity. Mean length of stay was 3.4 days. There were no device-related mortalities and no persistent endoleaks detected for the duration of follow-up. Aneurysm sac enlargement was not seen in any of the patients and complete resolution of the PAAA was noted at one year. Exclusion of AAA and other aortic pathology in patients with an associated malignancy can be performed with a relatively low procedure-related morbidity and mortality. In this population, stent-graft repair remains an individualized option with a multidisciplinary team necessary to explore this therapeutic approach.

Aged↗
PubMed2002

Stent-graft migration following endovascular repair of aneurysms with large proximal necks: anatomical risk factors and long-term sequelae.

PURPOSE: To evaluate the outcome of aortic endografts deployed in large infrarenal necks and to identify any association of preoperative aneurysm characteristics and postoperative morphological changes with the incidence of neck dilatation and device migration in this patient subset. METHODS: The records of 47 patients (41 men; mean age 74, range 55-84) with large aortic neck diameters treated with Talent stent-grafts from 1998 to 2001 were reviewed. Patients with anatomical criteria that precluded aneurysm exclusion with currently available devices were preferentially selected. Mean baseline aneurysm morphology included 27.6-mm (range 18-33.4) suprarenal and 28.1-mm (range 24-34) infrarenal neck diameters; the infrarenal neck length was 26 +/- 16 mm with angulation of 37 degrees +/- 18 degrees. Computed tomographic (CT) angiograms up to 3 years were analyzed using specialized interactive software; migration was defined as >1-cm change in the distance from the lower renal artery to the top of the device. Pre- and postoperative morphological characteristics of the aneurysm were compared between patients with and without migration. RESULTS: Of the 45 patients successfully treated, 40 had complete CT data for analysis. During a mean 17-month follow-up, 7 (17.5%) of the 40 devices exhibited distal migration. Six patients required secondary procedures; 5 were in the migration cohort. No preoperative anatomical characteristic or degree of neck dilatation over time was predictive of stent-graft migration. Aneurysm sac regression was significant at 1 (-0.09 +/- 4.90 mm) and 2 (-1.48 +/- 2.56 mm) years in endografts without migration (p<0.001). Distal endograft migration >1 cm predicted the need for secondary interventions (p<0.001), with 83% sensitivity and 94% specificity. CONCLUSIONS: Endovascular repair is successful in patients with large infrarenal necks and complex neck morphology. Changes in aneurysm remodeling over time were similar to reported observations in patients with more favorable neck criteria. Although no anatomical factor associated with migration could be identified from this analysis, distal displacement >1 cm correlated with the need for a secondary intervention.

Aged↗
PubMed2002

Regression of a descending thoracoabdominal aortic dissection following staged deployment of thoracic and abdominal aortic endografts.

PURPOSE: To describe the successful endovascular repair and regression of an extensive descending thoracoabdominal aortic dissection associated with thoracic and abdominal aortic aneurysms. CASE REPORT: An 83-year-old man presented with acute chest pain and shortness of breath. A descending thoracoabdominal aortic dissection that extended from near the left subclavian artery (LSA) to the right common iliac artery was found on computed tomography. Separate aneurysms in the thoracic and abdominal aorta were also identified. Staged endovascular procedures were undertaken to (1) close the single entry site and exclude the aneurysm in the thoracic aorta with an AneuRx thoracic stent-graft, (2) exclude the abdominal aneurysm and distal re-entry site with a bifurcated AneuRx endograft, and (3) treat a newly dilated thoracic segment between the LSA and first thoracic stent-graft. At 1 year, the false lumen had completely disappeared, the thoracic aneurysm had collapsed onto the endograft, and the abdominal aneurysm had shrunk by 30%. CONCLUSIONS: The potential to treat extensive aortic dissections with the hope that they might regress is promising, but repair of highly complex lesions involving one or more aneurysms in addition to the dissection requires meticulous imaging studies both preoperatively and intraprocedurally.

Aged↗