David C. Brewster

Determination of Cardiac Risk by Dipyridamole-Thallium Imaging before Peripheral Vascular Surgery

To evaluate the severity of coronary artery disease in patients with severe peripheral vascular disease requiring operation, we performed preoperative dipyridamole-thallium imaging in 54 stable patients with suspected coronary artery disease. Of the 54 patients, 48 had peripheral vascular surgery as scheduled without coronary angiography, of whom 8 (17 per cent) had postoperative cardiac ischemic events. The occurrence of these eight cardiac events could not have been predicted preoperatively by any clinical factors but did correlate with the presence of thallium redistribution. Eight of 16 patients with thallium redistribution had cardiac events, whereas there were no such events in 32 patients whose thallium scan either was normal or showed only persistent defects (P less than 0.0001). Six other patients also had thallium redistribution but underwent coronary angiography before vascular surgery. All had severe multivessel coronary artery disease, and four underwent coronary bypass surgery followed by uncomplicated peripheral vascular surgery. These data suggest that patients without thallium redistribution are at a low risk for postoperative ischemic events and may proceed to have vascular surgery. Patients with redistribution have a high incidence of postoperative ischemic events and should be considered for preoperative coronary angiography and myocardial revascularization in an effort to avoid postoperative myocardial ischemia and to improve survival. Dipyridamole-thallium imaging is superior to clinical assessment and is safer and less expensive than coronary angiography for the determination of cardiac risk.

The care of patients with an abdominal aortic aneurysm: The Society for Vascular Surgery practice guidelines

The Clinical Practice Council of the Society for Vascular Surgery charged a writing committee with the task of updating practice guidelines, initally published in 2003, for surgeons and physicians who are involved in the preoperative, operative, and postoperative care of patients with abdominal aortic aneurysms (AAA). This document provides recommendations for evaluating the patient, including risk of aneurysm rupture and associated medical co-morbidities, guidelines for selecting surgical or endovascular intervention, intraoperative strategies, perioperative care, long-term follow-up, and treatment of late complications. Decision making related to the care of patients with AAA is complex. Aneurysms present with varying risks of

Vascular complications associated with spontaneous aortic dissection

Three hundred twenty-five cases of spontaneous aortic dissection seen at two institutions between 1965 and 1986 were reviewed to assess the incidence, morbid sequelae, and specific management of aortic branch compromise. Noncardiac vascular complications occurred in 33% of the study group, and in these patients the overall mortality rate (51%) was significantly (p less than 0.001) higher than in patients without (29%) such complications. Although aortic rupture was the strongest correlate of mortality (90%), death specifically related to vascular occlusion was common when such occlusion occurred in the carotid, mesenteric, and renal circulation. There was a strong correlation between stroke and carotid occlusion (22/26 cases), yet specific carotid revascularization was only used during the chronic phase of the disease. Similarly, peripheral operation was ineffective in reducing the mortality rate in the setting of mesenteric (87%) and renal (50%) ischemia. Fifteen patients required either fenestration or graft replacement of the abdominal aorta for acute obstruction, rupture, or chronic aneurysm development. Thirty-eight patients (12%) demonstrated some degree of lower extremity ischemia, and one third of these required a direct approach on the abdominal aorta or iliofemoral segments to restore circulation. Selected patients with acute aortic dissection may require peripheral vascular operation in accordance with a treatment strategy that directs initial attention to the immediate life-threatening complications.

Initial experience with endovascular aneurysm repair: Comparison of early results with outcome of conventional open repair

PURPOSE To determine the safety, effectiveness, and problems encountered with endovascular repair of abdominal aortic aneurysm (AAA). Initial experience with endoluminal stent grafts was examined and compared with outcome for a matched concurrent control group undergoing conventional operative repair of AAA. METHODS Over a 3-year period, 30 patients underwent attempts at endovascular repair of infrarenal AAA. Of the 28 (93%) successfully implanted endografts, 8 were tube endografts, 8 bifurcated grafts, and 12 aortouniiliac grafts combined with femorofemoral bypass. Most of the procedures were performed in the past year because the availability of bifurcated and aortoiliac endografts markedly expanded the percentage of patients with AAA who might be treated with endoluminal methods. The follow-up period ranged from 1 to 44 months, with a mean value of 11 months. RESULTS Endovascular procedures demonstrated significant advantages with respect to reduced blood loss (408 versus 1287 ml), use of an intensive care unit (0.1 versus 1.75 days), length of hospitalization (3.9 versus 10.3 days), and quicker recovery (11 versus 47 days). Although the total number of postoperative complications was identical for the two groups, the nature of the complications differed considerably. Local and vascular complications characteristic of endovascular repair could frequently be corrected at the time of the procedure and tended to be less severe than systemic or remote complications, which predominated among the open surgical repair group. On an intent-to-treat basis, 23 (77%) of the 30 AAAs were successfully managed with endoluminal repair. The seven (23%) failures were attributable to two immediate conversions caused by access problems, three persistent endoleaks, one late conversion caused by AAA expansion, and one late rupture. CONCLUSIONS Although less definitive than those for conventional operations, these early results suggest that endovascular AAA repair offers considerable benefits for appropriate patients. The results justify continued application of this method of AAA repair, particularly in the treatment of older persons at high risk.

Long-term Outcomes After Endovascular Abdominal Aortic Aneurysm Repair: The First Decade

Objective:The proper role of endovascular abdominal aortic aneurysm repair (EVAR) remains controversial, largely due to uncertain late results. We reviewed a 12-year experience with EVAR to document late outcomes. Methods:During the interval January 7, 1994 through December 31, 2005, 873 patients underwent EVAR utilizing 10 different stent graft devices. Primary outcomes examined included operative mortality, aneurysm rupture, aneurysm-related mortality, open surgical conversion, and late survival rates. The incidence of endoleak, migration, aneurysm enlargement, and graft patency was also determined. Finally, the need for reintervention and success of such secondary procedures were evaluated. Kaplan-Meier and multivariate methodology were used for analysis. Results:Mean patient age was 75.7 years (range, 49–99 years); 81.4% were male. Mean follow-up was 27 months; 39.3% of patients had 2 or more major comorbidities, and 19.5% would be categorized as unfit for open repair. On an intent-to-treat basis, device deployment was successful in 99.3%. Thirty-day mortality was 1.8%. By Kaplan-Meier analysis, freedom from AAA rupture was 97.6% at 5 years and 94% at 9 years. Significant risk factors for late AAA rupture included female gender (odds ratio OR, 6.9; P = 0.004) and device-related endoleak (OR, 16.06; P = 0.009). Aneurysm-related death was avoided in 96.1% of patients, with the need for any reintervention (OR, 5.7 P = 0.006), family history of aneurysmal disease (OR, 9.5; P = 0.075), and renal insufficiency (OR, 7.1; P = 0.003) among its most important predictors. 87 (10%) patients required reintervention, with 92% of such procedures being catheter-based and a success rate of 84%. Significant predictors of reintervention included use of first-generation devices (OR, 1.2; P < 0.01) and late onset endoleak (OR, 64; P < 0.001). Current generation stent grafts correlated with significantly improved outcomes. Cumulative freedom from conversion to open repair was 93.3% at 5 through 9 years, with the need for prior reintervention (OR, 16.7; P = 0.001) its most important predictor. Cumulative survival was 52% at 5 years. Conclusions:EVAR using contemporary devices is a safe, effective, and durable method to prevent AAA rupture and aneurysm-related death. Assuming suitable AAA anatomy, these data justify a broad application of EVAR across a wide spectrum of patients.

Outcomes following endovascular abdominal aortic aneurysm repair (EVAR): an anatomic and device-specific analysis.

OBJECTIVE We performed a device-specific comparison of long-term outcomes following endovascular abdominal aortic aneurysm repair (EVAR) to determine the effect(s) of device type on early and late clinical outcomes. In addition, the impact of performing EVAR both within and outside of specific instructions for use (IFU) for each device was examined. METHODS Between January 8, 1999 and December 31, 2005, 565 patients underwent EVAR utilizing one of three commercially available stent graft devices. Study outcomes included perioperative (< or =30 days) mortality, intraoperative technical complications and need for adjunctive procedures, aneurysm rupture, aneurysm-related mortality, conversion to open repair, reintervention, development and/or resolution of endoleak, device related adverse events (migration, thrombosis, or kinking), and a combined endpoint of any graft-related adverse event (GRAE). Study outcomes were correlated by aneurysm morphology that was within or outside of the recommended device IFU. chi2 and Kaplan Meier methods were used for analysis. RESULTS Grafts implanted included 177 Cook Zenith (CZ, 31%), 111 Gore Excluder (GE, 20%), and 277 Medtronic AneuRx (MA, 49%); 39.3% of grafts were placed outside of at least one IFU parameter. Mean follow-up was 30 +/- 21 months and was shorter for CZ (20 months CZ vs 35 and 31 months for GE and MA, respectively; P < .001). Overall actuarial 5-year freedom from aneurysm-related death, reintervention, and GRAE was similar among devices. CZ had a lower number of graft migration events (0 CZ vs 1 GE and 9 MA); however, there was no difference between devices on actuarial analysis. Combined GRAE was lowest for CZ (29% CZ, 35% GE, and 43% MA; P = .01). Graft placement outside of IFU was associated with similar 5-year freedom from aneurysm-related death, migration, and reintervention (P > .05), but a lower freedom from GRAE (74% outside IFU vs 86% within IFU; P = .021), likely related to a higher incidence of graft thrombosis (2.3% outside IFU vs 0.3% within IFU; P = .026). The differences in outcome for grafts placed within vs outside IFU were not device-specific. CONCLUSION EVAR performed with three commercially available devices provided similar clinically relevant outcomes at 5 years, although no graft migration occurred with a suprarenal fixation device. As anticipated, application outside of anatomically specific IFU variables had an incremental negative effect on late results, indicating that adherence to such IFU guidelines is appropriate clinical practice.

Clinical experience with epidural cooling for spinal cord protection during thoracic and thoracoabdominal aneurysm repair

PURPOSE This report summarizes our experience with epidural cooling (EC) to achieve regional spinal cord hypothermia and thereby decrease the risk of spinal cord ischemic injury during the course of descending thoracic aneurysm (TA) and thoracoabdominal aneurysm (TAA) repair. METHODS During the interval July 1993 to Dec. 1995, 70 patients underwent TA (n = 9, 13%) or TAA (n = 61) (type I, 24 [34%], type II, 11 [15%], type III, 26 [37%]) repair using the EC technique. The latter was accomplished by continuous infusion of normal saline (4 degrees C) into a T11-12 epidural catheter; an intrathecal catheter was placed at the L3-4 level for monitoring of cerebrospinal fluid temperature (CSFT) and pressure (CSFP). All operations (one exception, atriofemoral bypass) were performed with the clamp-and-sew technique, and 50% of patients had preservation of intercostal vessels at proximal or distal anastomoses (30%) or by separate inclusion button (20%). Neurologic outcome was compared with a published predictive model for the incidence of neurologic deficits after TAA repair and with a matched (Type IV excluded) consecutive, control group (n = 55) who underwent TAA repair in the period 1990 to 1993 before use of EC. RESULTS EC was successful in all patients, with a 1442 +/- 718 ml mean (range, 200 to 3500 ml) volume of infusate; CSFT was reduced to a mean of 24 degrees +/- 3 degrees C during aortic cross-clamping with maintenance of core temperature of 34 degrees +/- 0.8 +/- C. Mean CSFP increased from baseline values of 13 +/- 8 mm Hg to 31 +/- 6 mm Hg during cross-clamp. Seven patients (10%) died within 60 days of surgery, but all survived long enough for evaluation of neurologic deficits. The EC group and control group were well-matched with respect to mean age, incidence of acute presentations/aortic dissection/aneurysm rupture, TAA type distribution, and aortic cross-clamp times. Two lower extremity neurologic deficits (2.9%) were observed in the EC patients and 13 (23%) in the control group (p < 0.0001). Observed and predicted deficits in the EC patients were 2.9% and 20.0% (p = 0.001), and for the control group 23% and 17.8% (p = 0.48). In considering EC and control patients (n = 115), variables associated with postoperative neurologic deficit were prolonged (> 60 min) visceral aortic cross-clamp time (relative risk, 4.4; 95% CI, 1.2 to 16.5; p = 0.02) and lack of epidural cooling (relative risk, 9.8; 95% CI, 2 to 48; p = 0.005). CONCLUSION EC is a safe and effective technique to increase the ischemic tolerance of the spinal cord during TA or TAA repair. When used in conjunction with a clamp-and-sew technique and a strategy of selective intercostal reanastomosis, EC has significantly reduced the incidence of neurologic deficits after TAA repair.

Cancer prevalence in the United Kingdom: estimates for 2008

Background:Identifying and addressing the requirements of cancer survivors is currently a high priority for the NHS, yet little is known about the population of cancer survivors in the United Kingdom.Methods:Data from cancer registries in England, Northern Ireland, Scotland and Wales were analysed to provide limited-duration prevalence estimates for 2004. Log-linear regression models were used to extend these to complete prevalence estimates. Trends in prevalence from 2000 to 2004 were used to project complete prevalence estimates forward from 2004 to 2008.Results:We estimated that in total, there were 2 million cancer survivors in the United Kingdom at the end of 2008, ∼3% of the population overall and 1 in 8 of those aged 65 years and more. Prostate and female breast cancers were the most prevalent. The number of cancer survivors is increasing by ∼3% each year. Estimates are also provided by time since diagnosis.Conclusion:These estimates are the most up-to-date available, and as such will be useful for statutory and voluntary sector organisations that are responsible for planning and providing treatment and support to cancer survivors in the United Kingdom.

Transperitoneal versus retroperitoneal approach for aortic reconstruction: A randomized prospective study*

A prospective, randomized study was conducted to compare the retroperitoneal versus transperitoneal approach for elective aortic reconstruction. One hundred thirteen patients (transperitoneal = 59, retroperitoneal = 54) were randomized between March 1987 and October 1988. In addition, to assess the changing course of patients undergoing aortic reconstruction similar data were gathered retrospectively on a group of 56 patients undergoing aortic reconstruction by the same surgeons performed via a transperitoneal approach in 1984 to 1985. Randomized patients were identical in age, male to female ratio, smoking history, incidence and severity of cardiopulmonary disease, indication for operation, and use of epidural anesthetics. Details of operation including operative and aortic cross-clamp times, crystalloid and transfusion requirements, degree of hypothermia on arrival at the intensive care unit, and perioperative fluid and blood requirements did not differ significantly for patients undergoing transperitoneal versus retroperitoneal reconstruction. Respiratory morbidity, as assessed by percent of patients requiring postoperative ventilation, deterioration in pulmonary function tests, and the incidence of respiratory complications, was identical in randomized patients. Other aspects of postoperative recovery including recovery of gastrointestinal function, the requirement for narcotics, metabolic parameters of operative stress, the incidence of major and minor complications, and the duration of hospital stay were similar for randomized patients undergoing transperitoneal and retroperitoneal reconstruction. When compared to retrospectively reviewed patients having aortic reconstruction, randomized patients undergoing transperitoneal and retroperitoneal operations had highly significant (p less than 0.001) reductions in postoperative ventilation, transfusion requirements, and length of hospital stay. Such trends were all independent of transperitoneal versus retroperitoneal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative early and late cardiac morbidity among patients requiring different vascular surgery procedures

PURPOSE The evaluation of coronary artery disease (CAD) in patients undergoing vascular surgery can provide information with respect to perioperative and long-term risk for CAD-related events. However, the extent to which the required surgical procedure itself imparts additional risk beyond that dictated by the presence of CAD determinants remains in question. The purpose of this study was to quantify the relative contributions of specific vascular procedures and CAD markers on perioperative and long-term cardiac risk. METHODS The study cohort comprised 547 patients undergoing vascular surgery from two medical centers who underwent clinical evaluation, dipyridamole thallium testing, and either aortic (n = 321), infrainguinal (n = 177), or carotid (n = 49) vascular surgery between 1984 and 1991. Perioperative and late cardiac risk of fatal or nonfatal myocardial infarction (MI) was compared for the three procedures before and after adjustment for the influence of comorbid factors. These adjusted estimates may be regarded as the component of risk because of type of surgery. RESULTS Perioperative MI occurred in 6% of patients undergoing aortic and carotid artery surgery, and in 13% of patients undergoing infrainguinal procedures (p = 0.019). Significant (p < 0.05) predictors of MI were history of angina, fixed and reversible dipyridamole thallium defects, and ischemic ST depression during testing. Although patients undergoing infrainguinal procedures exhibited more than twice the risk for perioperative MI compared with patients undergoing aortic surgery (relative risk: 2.4[1.2 to 4.5, p = 0.008]), this value was reduced to insignificant levels (1.6[0.8 to 3.2, p = 0.189]) after adjustment for comorbid factors. There was little change in comparative risk between carotid artery and aortic procedures before (1.0[0.3 to 3.6, p = 0.95]) or after (0.6[0.2 to 2.3, p = 0.4]) covariate adjustment. The 4-year cumulative event-free survival rate was 90% +/- 2% for aortic, 74% +/- 5% for infrainguinal, and 78% +/- 7% for carotid artery procedures (p = 0.0001). Predictors of late MI included history of angina, congestive heart failure, diabetes, fixed dipyridamole thallium defects, and perioperative MI. Patients undergoing infrainguinal procedures exhibited a threefold greater risk for late events compared with patients undergoing aortic procedures (relative risk: 3.0[1.8 to 5.1, p = 0.005]), but this value was reduced to 1.3(0.8 to 2.3, p = 0.32) after adjustment. Long-term risk among patients undergoing carotid artery surgery was less dramatically altered by risk factor adjustment. CONCLUSION In current practice, among patients referred for dipyridamole testing before operation, observed differences in cardiac risk of vascular surgery procedures may be primarily attributable to readily identifiable CAD risk factors rather than to the specific type of vascular surgery. Thus the cardiac and diabetic status of patients should be given careful consideration whenever possible, regardless of surgical procedure to be performed.