Multistate utilization, processes, and outcomes of carotid endarterectomy.

OBJECTIVES: The purpose of this study was to describe variation in utilization, care processes, and outcomes for carotid endarterectomy (CEA) procedures in 10 states. METHODS: We reviewed the medical records of Medicare patients who underwent 10,561 CEA procedures between June 1, 1995, and May 31, 1996, in 10 different states to determine indications, care processes, and outcomes. This study also included medical record review of hospital readmissions within 30 days of the procedure and identification of out-of-hospital deaths from the Medicare beneficiary files. RESULTS: Utilization rates of CEA varied from 25.7 to 38.4 procedures per 10,000 Medicare beneficiaries among states. The overall combined event rate (30-day stroke or mortality) was 5.2% for primary CEA alone (n = 9945). The mortality rate was 1.5%, and the nonfatal stroke rate was 3.7%. Combined event rates (CEA alone) by surgical indication were 7.7% for stroke (n = 1037), 7.4% for transient ischemic attack (n = 1304), 5.3% for nonspecific symptoms (n = 3713), and 3.7% for asymptomatic patients (n = 3891). The combined event rates (CEA alone) among states ranged from 4.1% to 7.7% with the event rates in asymptomatic patients ranging from 2.3% to 6.7%. In a multivariate analysis (correcting for indication), the use of preoperative antiplatelet agents (odds ratio [OR], 0.70), intraoperative heparin (OR, 0.49), and patch angioplasty (OR, 0.73) was significantly associated with lower combined event rates. There were significant differences among states in the use of preoperative antiplatelet therapy (range, 56%-70%) and patch angioplasty (range, 11%-49%). Combined event rates for repeat procedures (n = 380) and CEA combined with coronary artery bypass grafting (n = 236) were 6.3% and 17.4%, respectively. CONCLUSIONS: The striking variation among states suggests that there is room for improvement in the utilization, care processes, and outcomes of CEA. All surgeons performing CEA should participate in outcome assessment and adopt protocols that include the routine administration of antiplatelet agents preoperatively, the use of heparin intraoperatively, and patch angioplasty of the endarterectomy site.

Long-term follow-up and patient satisfaction after surgery for thoracic outlet syndrome.

The purpose of this study was to review the long-term outcomes, particularly patient satisfaction, of patients surgically treated for thoracic outlet syndrome (TOS). All patients who had undergone surgery for TOS at the University of Iowa Hospitals and Clinics between 1988 and 1999 were reviewed. A retrospective chart review of 29 patients (36 operations) was performed. In addition, 20 (69%) of the patients were able to be contacted for a phone survey. There was no operative mortality. Specific neurologic complications occurred in 4/36 operations (11%) including one brachial plexus traction palsy, two phrenic nerve palsies, and one long thoracic nerve palsy. All nerve palsies were either mild or temporary. Mean follow-up was 4 years. On phone survey, 80% of the patients were actively employed. Twenty-seven percent reported that they had an excellent result, 58% reported they had a good result, 8% reported that they had a fair result, and 8% had a poor result. If they had it to do over again, 85% of the patients would have the same surgery again for relief of TOS.

Challenges in comparing risk-adjusted bypass surgery mortality results: results from the Cooperative Cardiovascular Project.

OBJECTIVES: We sought to evaluate the predictive accuracy of four bypass surgery mortality clinical risk models and to examine the extent to which hospitals' risk-adjusted surgical outcomes vary depending on which risk-adjustment method is applied. BACKGROUND: Cardiovascular "report cards" often compare risk-adjusted surgical outcomes; however, it is unclear to what extent the risk-adjustment process itself may affect these metrics. METHODS: As part of the Cooperative Cardiovascular Project's Pilot Revascularization Study, we compared the predictive accuracy of four bypass clinical risk models among 3,654 Medicare patients undergoing surgery at 28 hospitals in Alabama and Iowa. We also compared the agreement in hospital-level risk-adjusted bypass outcome performance ratings depending on which of the four risk models was applied. RESULTS: Although the four risk models had similar discriminatory abilities (C-index, 0.71 to 0.74), certain models tended to overpredict mortality in higher-risk patients. There was high correlation between a hospital's risk-adjusted mortality rates regardless of which of the four models was used (correlation between risk-adjusted rating, 0.93 to 0.97). In contrast, there was limited agreement in which hospitals were identified as "performance outliers" depending on which risk-adjustment model was used and how outlier status was defined. CONCLUSIONS: A hospital's risk-adjusted bypass surgery mortality rating, relative to its peers, was consistent regardless of the risk-adjustment model applied, supporting their use as a means of provider performance feedback. Designation of performance outliers, however, can vary significantly depending on the benchmark and methods used for this determination.

Impact of quality improvement activities on care for acute myocardial infarction.

OBJECTIVE: To examine the relationship between quality improvement activities reported to a peer review organization (PRO) and improvements in quality of care for patients with acute myocardial infarction (AMI). DESIGN: Time-series, comparative study of changes in care for AMI patients from 1992 to 1995 in hospitals reporting self-measurement or system changes compared to all other hospitals in the state. SETTING: One-hundred and seventeen acute care hospitals in Iowa. STUDY PARTICIPANTS: Patients hospitalized with a principal diagnosis of AMI. INTERVENTIONS: Each hospital was given hospital-specific performance data, statewide aggregate data, and peer comparisons and was asked to provide the PRO with a plan to improve care for AMI patients. MEASUREMENTS: Chart audits were performed before and after the intervention. Quality of care was based on eight explicit process measures of the quality of AMI care (quality indicators). RESULTS: Statewide, quality of care improved on five out of eight quality indicators. Of the 117 hospitals, 44 (38%) reported that they had implemented their own measurement activities or systematic improvements. These 44 hospitals showed significantly greater improvements than the other hospitals in use of aspirin during the hospitalization, recommendations for aspirin at discharge, and prescriptions for beta blockers at discharge. CONCLUSIONS: While quality of care for AMI patients throughout Iowa is improving, the pace of improvement is greatest in hospitals reporting that they are measuring their own performance or implementing systematic changes in care processes. Continued efforts to encourage hospitals to implement these types of improvement activities are warranted.

Improving the outcomes of carotid endarterectomy: results of a statewide quality improvement project.

OBJECTIVE: The purpose of this study was to establish the statewide outcomes for carotid endarterectomy (CEA) and to facilitate improvement in outcomes through feedback, peer discussion, and ongoing process and outcome measurement. METHODS: The Medicare Part A claims files were used to identify all Medicare patients undergoing CEA in Iowa during two 12-month time periods (January 1994-December 1994 and June 1995-May 1996). Medical record abstraction was used to obtain surgical indications, perioperative care process, and outcome information. Confidential reports were provided to each hospital (N = 30) where the procedure was performed. Surgeons performing the procedure (N = 79) were invited to meetings to discuss care process variation and outcomes. Voluntary participation was solicited in a standardized program of ongoing hospital-based data collection of CEA process and outcome data. RESULTS: The statewide combined stroke or mortality rate decreased from 7.8% in 1994 to 4.0% in the 1995 to 1996 time period (P <.001). Fourteen hospitals, accounting for 74% of the statewide cases, participated in ongoing data collection. The combined stroke or mortality rate in these hospitals decreased significantly (P <.05) over time from 6.5% (1994) to 3.7% (1995-1996) to 1.8% (June 1997-May 1998). The use of intraoperative assessment of the operative site (20% in 1994, 46% in 1997-1998) and patch angioplasty (14% in 1994, 30% in 1997-1998) increased significantly during this time in the participating hospitals. CONCLUSIONS: Confidential feedback of outcome and process data for CEA may lead to change in perioperative care processes and improved outcomes. Standardized community-based outcome analysis should become routine for CEA to ensure that optimum results are being achieved.

The differences in electroencephalographic changes in patients undergoing carotid endarterectomies while under local versus general anesthesia.

OBJECTIVE: This study compared the electroencephalographic (EEG) changes occurring during carotid occlusion in 225 consecutive patients undergoing carotid endarterectomies performed by two surgeons, one using local and the other using general anesthesia. METHODS: A retrospective review of patients undergoing carotid endarterectomies for carotid occlusive disease was conducted. EEG changes associated with intraoperative ischemia (decreased amplitude, generalized slowing, and loss of fast activity) resulting in the need for an indwelling arterial shunt were recorded for the two anesthesia groups. To determine the similarities or differences between the two groups, the groups were compared regarding age, risk factors, and indications for surgery. RESULTS: Significant EEG changes were noted in 6 of 96 patients (6.3%) in the local anesthesia group versus 19 of 121 patients (15.7%) in the general anesthesia group. EEG changes consisted solely of generalized slowing in the local anesthesia group, whereas a more varied spectrum was observed in the general anesthesia group. The two groups were similar regarding age and risk factors. Although the local anesthesia group had more asymptomatic patients, symptomatic patients did not have a greater incidence of EEG changes. CONCLUSION: There is a large difference in EEG changes potentially requiring shunt placement in patients undergoing surgery while under local (6.3%) versus general (15.7%) anesthesia. This could not be explained based on age, risk factors, interpretation of EEG findings, or indications between the two groups. We conclude that EEG monitoring may be insensitive and may fail to detect ischemia in patients who are under regional anesthesia. Alternately, the presence of general anesthetics may alter the character of the EEG findings and increase the sensitivity of EEG monitoring to ischemic events.

Improving the quality of care for Medicare patients with acute myocardial infarction: results from the Cooperative Cardiovascular Project.

CONTEXT: Medicare has a legislative mandate for quality assurance, but the effectiveness of its population-based quality improvement programs has been difficult to establish. OBJECTIVE: To improve the quality of care for Medicare patients with acute myocardial infarction. DESIGN: Quality improvement project with baseline measurement, feedback, remeasurement, and comparison samples. SETTING: All acute care hospitals in the United States. PATIENTS: Preintervention and postintervention samples included all Medicare patients in Alabama, Connecticut, Iowa, and Wisconsin discharged with principal diagnoses of acute myocardial infarctions during 2 periods, June 1992 through December 1992 and August 1995 through November 1995. Indicator comparisons were made with a random sample of Medicare patients in the rest of the nation discharged with acute myocardial infarctions from August 1995 through November 1995. Mortality comparisons involved all Medicare patients nationwide with inpatient claims for acute myocardial infarctions during 2 periods, June 1992 through May 1993 and August 1995 through July 1996. INTERVENTION: Data feedback by peer review organizations. MAIN OUTCOME MEASURES: Quality indicators derived from clinical practice guidelines, length of stay, and mortality. RESULTS: Performance on all quality indicators improved significantly in the 4 pilot states. Administration of aspirin during hospitalization in patients without contraindications improved from 84% to 90% (P< .001), and prescription of beta-blockers at discharge improved from 47% to 68% (P < .001). Mortality at 30 days decreased from 18.9% to 17.1% (P = .005) and at 1 year from 32.3% to 29.6% (P < .001). These improvements in quality occurred during a period when median length of stay decreased from 8 days to 6 days. Performance on all quality indicators except reperfusion was better in the pilot states than in the rest of the nation in 1995, and the differences were statistically significant for aspirin use at discharge (P < .001), beta-blocker use (P < .001), and smoking cessation counseling (P = .02). Postinfarction mortality was not significantly different between the pilot states and the rest of the nation during the baseline period, although it was slightly but significantly better in the pilot states during the follow-up period (absolute mortality difference at 1 year, 0.9%; P = .004). CONCLUSIONS: The quality of care for Medicare patients with acute myocardial infarction has improved in the Cooperative Cardiovascular Project pilot states. Performance on the defined quality indicators appeared to be better in the pilot states than in the rest of the nation in 1995 and was associated with reduced mortality.

A comparative evaluation of femorofemoral crossover bypass and iliofemoral bypass for unilateral iliac artery occlusive disease.

The purpose of this study was to compare the results of extra-anatomic femorofemoral crossover bypass grafting to the anatomic iliofemoral bypass grafting procedure in the treatment of patients with unilateral iliac artery occlusive disease with respect to patency and limb salvage. The records of all patients with unilateral iliac artery disease who underwent revascularization between January 1988 and December 1995 at the University of Iowa Hospitals and Clinics (UIHC) were retrospectively reviewed; 108 patients were identified and divided into two groups. Group I (n=68; male/female=44/24) was composed of all patients who underwent a femorofemoral crossover extra-anatomic bypass. All patients who underwent an iliofemoral anatomic bypass constituted group II (n=40; male/female=24/16). The mean age for group I was 60 years (range 28-87) and for group II, 54 years (range 14-86). The medical risk factors between both groups were comparable. Except for the higher incidence of gangrene in group II the indications for surgery were comparable between both groups. A polytetrafluoroethylene graft was used in 88% of group I patients and in 90% of group II patients (NS). In the remaining patients, an autogenous vein conduit was used. Two patients from group I (2.9%) died in the perioperative period (NS). Graft patency was assessed by clinical evaluation, Doppler-derived ankle/brachial indices, and color duplex imaging. The cumulative primary and secondary patency rates, limb salvage, and patient survival were calculated by use of life table analysis (SE<0.1). The need for simultaneous outflow and inflow procedures at the time of surgery was comparable between both groups. The proportion of patients who underwent further revascularization during follow-up was also comparable. The 5-year primary and secondary graft patency rates were 81.7% and 90.3%, in group I and 61.3% and 80.5% in group II. Although the difference between both groups was not significant there was a tendency toward higher rates with femorofemoral bypass. The 5-year survival rates of 80.3% for group I and 73.3% for group II were comparable. These data suggest that there is no significant difference in the long-term results between the femorofemoral crossover bypass grafts and iliofemoral grafts. Both procedures result in acceptable patency and limb salvage rates. The femorofemoral bypass is, however, more attractive, for it can be performed under local anesthesia if needed and does not involve the creation of the retroperitoneal incision necessary with the iliofemoral bypass.

Entering the ninth decade is not a contraindication for carotid endarterectomy.

The role of carotid endarterectomy (CEA) in stroke prevention is now better defined. However, its role in patients older than 79 years of age is controversial. This group of patients has been excluded in most clinical trials. In this study the authors reviewed their experience with CEA patients >79 years old. The records of all patients older than 79 years of age who underwent a CEA in a recent time period from January 1988 to December 1996 were retrospectively reviewed. Forty-one patients (31 men, 10 women) were identified by computer search. The indication for operation included transient ischemic attack in 12 (29.3%), amaurosis fugax in nine (22%), stroke in two (4.9%), and nonhemispheric symptoms in three (7.3%). Fifteen patients (36.6%) were asymptomatic. Medical risk factors included coronary artery disease in 26 (63.4%), hypertension in 22 (53.7%), and smoking in 12 (29.3%). The procedure was performed under EEG monitoring in all patients. General anesthesia was administered in 37 (90%) and regional anesthesia in four (10%). Shunts were used in four (10%) patients. The internal carotid artery was patched in 16 patients (39%). One patient (2.4%) developed a perioperative stroke and only one patient developed perioperative myocardial infarction (MI). None of the patients died within 30 days of surgery. In addition to the one MI case, five patients developed minor complications. The average length of time for stay after CEA was 3.4 days. Patients were followed up for an average of 20.7 months. Six patients died during follow-up. Four of those died from an MI and two from a stroke. The authors conclude that with proper selection of patients, CEA is safe in the octogenarian. Age alone should not be a contraindication for CEA.

Is color duplex surveillance of infrainguinal polytetrafluoroethylene grafts worthwhile?

BACKGROUND: Unlike vein bypasses, the role of duplex surveillance of infrainguinal prosthetic bypass grafts is controversial. The purpose of this study was to evaluate the adequacy of color duplex surveillance in identifying failing infrainguinal polytetrafluoroethylene (PTFE) bypass grafts and to assess its value in predicting continued bypass patency. METHOD: The surveillance data of primarily patent PTFE bypass grafts were compared with those of revised/occluded PTFE grafts. Ninety-five patients underwent 102 infrainguinal PTFE bypass grafts from January 1991 to December 1996 and were enrolled in a duplex surveillance program at 1 month postoperatively, every 3 months in the first year, every 6 months in the second year, and yearly thereafter. RESULTS: Seventy grafts remained primarily patent, 5 were revised and 27 occluded. There was no significant difference in the mean age, gender, indication for surgery, type of original procedure, or duration of follow-up between both groups. Four hundred and seven duplex surveillance data were available for analysis. Focal increase in peak systolic velocity (PSV) 3 x the adjacent segment or low flow manifested by PSV <45 cm/sec were considered abnormal. In the primarily patent group, 5 bypasses had abnormal duplex surveillance and were found to have no abnormality on angiogram and remained patent during the study period. In the revised/occluded group, duplex surveillance was abnormal in 8 bypasses. Twenty-four bypasses occluded without any predicting abnormalities on their last duplex examination, which was performed within 3 months from the occlusion in the majority of the patients. In the 27 occluded bypasses, no intervention was necessary following the occlusion in 7 grafts because of mild or no symptoms. Two patients were treated with a primary amputation and 2 had new bypasses. In 16 occluded grafts, salvage of the PTFE bypass was attempted. Ten of these grafts were patent at the end of the follow-up. The sensitivity of duplex surveillance was 25% with a positive predictive value of 61.5%. CONCLUSION: Duplex surveillance of infrainguinal PTFE bypass grafts has a low yield and is inadequate at predicting continued bypass patency.

Renal hilar Doppler analysis is of value in the management of patients with renovascular disease.

BACKGROUND: An increasing interest in the role of Doppler ultrasound and duplex scan in screening for renovascular hypertension has recently been noted. We conducted this study to define the role of renal hilar Doppler ultrasound (RHDU) in evaluating renal artery stenosis and its value in the postoperative follow-up after renal revascularization. METHODS: One hundred and fourteen patients are included in this study with a mean age of 63.7 (11 to 89) years. Seventy-two patients underwent renal revascularization. The most frequent revascularization procedure was renal artery bypass in 82%. The RHDU results were compared with 130 angiograms done within 1 month of the RHDU study. The Doppler velocity signal in a segmental artery in the renal parenchyma was recorded, and the waveform was analyzed. An acceleration index (AI) less than 3.78 KHz/sec/MHz and an acceleration time (AT) greater than 0.1 seconds were used to indicate the presence of a significant renal artery stenosis. RESULTS: The overall technical success rate of all RHDU studies was 93.5%. The AI value was higher in the group of patients with normal renal arteries than those with a stenosis (4.7 +/- 1.4 KHz/sec/MHz versus 1.23 +/- 1.13 kHz/sec/MHz, respectively, P <0.0001), and the AT was lower in the former group compared with the latter (0.052 +/- 0.011 sec versus 0.122 +/- 0.069 sec, P <0.0001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for AI were 89%, 92%, 85%, 94%, and 92%, respectively; and for AT were 62.5%, 97.5%, 91%, 86.5%, and 87% respectively. There was a significantly high agreement between the AI and AT results and those of arteriography (Kappa of 0.82 and 0.66, respectively, P < 0.0001). There were 10.6% kidneys with multiple renal arteries by arteriography. In these kidneys the accuracy was lower for both AI and AT and the agreement with arteriography was nonsignificant. In the postoperative period the accuracy of RHDU was 86% for AI and 95% for AT. CONCLUSIONS: Renal hilar Doppler ultrasound has a high accuracy and agreement with arteriography in the diagnosis of renal artery stenosis. Its value is limited by the presence of multiple renal arteries, renal artery occlusion, and high incidence of postoperative false-positive results. It can be useful as a noninvasive screening test for patients suspected of having renal artery stenosis and for surveillance following renal revascularization.

Cardiac screening tests prior to lower extremity revascularization: routine versus selective application.

Coronary artery disease (CAD) is the most important comorbidity associated with peripheral vascular disease. Consensus on the optimal approach to the cardiac evaluation of patients presenting for peripheral vascular operations has not been achieved. We developed a large experience with routine cardiac screening using dipyridamole thallium scintigraphy (DTS) and radionuclide ventriculography. The incidence of reversible ischemia on DTS and the subsequent documentation of severe CAD on coronary angiography was similar in vascular patients with a history of CAD (angina or myocardial infarction) and those with a negative CAD history. However, the analysis of overall risks and benefits does not support a recommendation for routine screening. We suggest that selection of patients for screening should be based on the estimated benefit of coronary revascularization for the individual patient considering both perioperative and long-term survival. In addition, screening is also considered if identification of unsuspected CAD will alter the decision to perform the proposed peripheral vascular operation. Thus, the older patient who requires an infrainguinal bypass for limb-threatening ischemia is unlikely to benefit from cardiac screening. Documentation of the extent of CAD with screening studies may be beneficial in younger patients or in patients with claudication.

Determinants of appropriate use of angiotensin-converting enzyme inhibitors after acute myocardial infarction in persons > or = 65 years of age.

We sought to determine how often angiotensin-converting enzyme (ACE) inhibitors are prescribed as a discharge medication among eligible patients > or = 65 years old with an acute myocardial infarction; to identify patient characteristics associated with the decision to prescribe ACE inhibitors; and to determine the factors associated with the decision to obtain an evaluation of left ventricular function among patients who have no contraindications to ACE inhibitors. We addressed these aims with an observational study of consecutive elderly Medicare beneficiary survivors of an acute myocardial infarction hospitalized in Alabama, Connecticut, Iowa, and Wisconsin between June 1992 and February 1993. Among the 5,453 patients without a contraindication to ACE inhibitors at discharge, 3,528 (65%) had an evaluation of left ventricular function. Of the 1,228 patients without a contraindication to ACE inhibitors who had a left ventricular ejection fraction < or = 40%, 548 (45%) were prescribed the medication at discharge. In a multivariable analysis, an increased prescribed use of ACE inhibitors at discharge was correlated with several factors, including diabetes mellitus, congestive heart failure, ventricular tachycardia, and loop diuretics as a discharge medication. Patients admitted after the publication of the Survival and Ventricular Enlargement (SAVE) trial were significantly more likely to receive ACE inhibitors, although the absolute improvement in utilization was small in the 6 months after the trial results were published. In conclusion, improving the identification of appropriate patients for ACE inhibitors and increasing the prescription of ACE inhibitors for ideal patients may provide an excellent opportunity to improve care.

Peritoneal venous shunting for the treatment of lymphatic ascites following retroperitoneal lymph node dissection.

We report a case of refractory lymphatic ascites following retroperitoneal lymph node dissection and venacavectomy. Placement of a Denver peritoneal venous shunt resulted in resolution of the ascites and marked improvement in the patient's nutritional parameters. Shunt occlusion 2 months following placement demonstrated no recurrence of the ascites. This technique may prove useful in the management of lymphatic ascites associated with radical retroperitoneal surgery.

Revascularization of the ischemic diabetic foot using popliteal artery inflow.

Between March 1988 and June 1994, 35 popliteal to distal artery vein bypasses were done in 32 diabetic patients. There were 16 males and 16 females with an average age of 60 years. Eighteen patients (56%) had insulin dependent diabetes mellitus. Medical risk factors included coronary artery disease (CAD) in 15 (47%), hypertension in 15 (47%), chronic renal failure (CRF) in 9 (28%), and cigarette smoking in 10 (31%). Indications for revascularization were: non-healing ulcerations in 18 (51%), gangrene in 15 (43%), and rest pain in 2 (6%). The distal anastomosis was to the posterior tibial artery in 9, anterior tibial artery in 8, dorsalis pedis artery in 10 and peroneal artery in 8 cases. All the bypasses were done with autogenous saphenous veins (in-situ 11, reversed 17, and free non-reversed 7). The limbs were graded into three groups based on the preoperative angiographic evaluation of their pedal arch: patent arch (Grade "0"), partial occlusion of the arch (grade "1.5") and little or no arch visualized (Grade "3"). Eight limbs had Grade "0", 16 had Grade "1.5" and 11 had Grade "3" pedal circulation. Bypass follow up was done by clinical exam and color duplex surveillance (CDS) for a mean duration of 24 months. CDS identified 4 failing bypasses which were surgically revised and have subsequently remained patent. There were 3 bypass occlusions which resulted in a major amputation in 2 patients. Three additional major amputations were performed for persisting infection despite a patent bypass. By life table analysis the cumulative primary & secondary patency and limb salvage rates for this group of diabetic patients were 75% at 2 years, 89% at 3 years and 82% at 3 years respectively (S.E. < 10%). The 3 bypass occlusions, which occurred at 1 week, 5 weeks, and 20 months, were in patients with both CRF and Grade "3" foot circulation (significantly different outcome compared to the rest of the group, by chi 2 test, p < 0.05). Good results can be achieved in the majority of diabetic patients undergoing short popliteal-distal bypasses. However, the combination of chronic renal failure and very limited foot circulation (Grade "3") has a significant adverse outcome.

Selection of patients for cardiac evaluation before peripheral vascular operations.

PURPOSE: This study evaluated the value of preoperative cardiac screening with dipyridamole thallium scintigraphy and radionuclide ventriculography in vascular surgery patients. METHODS: From July 1, 1989, to Dec. 31, 1991, we routinely (irrespective of the patient's cardiac history or symptomatology) performed dipyridamole thallium scintigraphy (DTS) and radionuclide ventriculography (RVG) in 394 patients being considered for an elective vascular operation. Patients with reversible defects on DTS underwent coronary arteriography. RESULTS: DTS results were normal in 146 patients (37%), showed a fixed defect in 75 (19%), and showed a reversible defect in 173 (44%). Patients with and without a history of angina or myocardial infarction had identical rates of reversible defects. Normal left ventricular function (> 50%) was noted in 76% of the patients; 17% had moderate dysfunction (35% to 50%) and 7% had a low ejection fraction (< 35%). The finding of severe coronary artery disease led to cardiac revascularization in 17 patients who had no prior history of cardiac disease and in 13 patients with a history of angina or myocardial infarction. Two deaths and nine major complications were associated with coronary arteriography and cardiac revascularization. Vascular procedures (144 aortic, 53 carotid, 146 infrainguinal) were ultimately performed in 343 patients, with a mortality rate of 1.7% (3.5% aortic, 0% carotid, and 0.7% infrainguinal bypass). The nonfatal perioperative myocardial infarction rate was 2.0%. We monitored all 394 patients for cardiovascular events, with a mean follow-up of 40 months. Patients who underwent cardiac revascularization had a 4-year survival rate of 75%, which was similar to those with a normal DTS. Late cardiac events were significantly more frequent in patients who had either a reversible DTS or RVG < 35%. CONCLUSIONS: Routine cardiac screening of vascular surgery patients had similar impact on patients irrespective of their prior history or current symptoms suggesting coronary artery disease. Routine screening did not result in substantial benefit. Screening studies such as DTS or RVG may be most useful as part of an overall risk versus benefit assessment in patients without active symptoms of coronary artery disease who have less compelling indications for vascular intervention (claudication, moderate-sized aortic aneurysms, or asymptomatic carotid disease).

Lateral approach to the popliteal and crural vessels for limb salvage.

Twenty-one patients underwent 23 bypasses for limb salvage via a lateral approach with subcutaneous graft tunneling. The reasons for utilizing a lateral approach were medial infection (10 bypasses), scarring from previous surgery (six), limited vein length available (three), prior local radiotherapy (two) and 'high risk' groin (two). The target artery was the anterior tibial in 16 cases, the peroneal in three, the above-knee popliteal in three and the dorsalis pedis in one. The median (range) follow-up was 22(<1-52) months. There were three early (within 30 days) and four late bypass occlusions, three of which occurred in previously revised bypasses and one in a non-compliant patient. The primary patency at 1 year was 61% and the secondary patency 86%. Only one amputation was required in the whole series. The lateral approach represents a simple solution to threatened limbs in otherwise difficult or complicated situations and may be the ideal approach for free vein grafts to the anterior tibial and distal peroneal arteries.

The aortic polytetrafluoroethylene graft: further experience.

OBJECTIVES: We analysed our results with the use of aortic polytetrafluoroethylene PTFE grafts over the last 7.5 years. A historical comparison was also made between the results with non-stretch PTFE (NS-PTFE) (1987-91) and stretch PTFE (S-PTFE) grafts (1991-94). MATERIALS: 244 infrarenal aortic replacements or bypasses with PTFE grafts were performed at the University of Iowa Hospitals and Clinics from January 1987 to June 1994. Infrarenal aortic replacement was indicated for aortic aneurysmal disease in 192 patients (elective 151, symptomatic 20, ruptured 21) and bypass for aorto-iliac occlusive disease in 52 patients (disabling claudication 28, limb salvage 24). Patients ranged in age from 37 to 93 years (mean 68 years). There were 161 males and 83 females. Medical risk factors included hypertension (55%), coronary artery disease (31%), COPD (23%), diabetes mellitus (12%) chronic renal failure (9%), and smoking (61%). Aortic replacement or bypass was done with a NS-PTFE graft in 108 patients (44%) and a S-PTFE graft in 136 patients (56%). Postoperative ultrasound (US) scans and/or CT-studies were available in 40 patients with NS-PTFE and 26 patients with S-PTFE grafts. MAIN RESULTS: The 30 day operative mortality was: elective AAA patients (1.3%), symptomatic AAA patients (10%), ruptured AAA patients (48%), limb salvage patients (4.1%) and disabling claudication patients (0%). Graft related complications included five graft limb thromboses (4 NS-PTFE, 1 S-PTFE). Two thromboses occurred perioperatively and the three others at 24, 28 and 30 months postoperatively. Two other graft related complications included a mixed pseudomonas and streptococcus groin infection with a culture negative perigraft fluid collection occurring 3 weeks following surgery (NS-PTFE), and distal aortic anastomotic suture line bleed on the first postoperative day following replacement of a ruptured AAA with a S-PTFE graft. Based on US and/or CT imaging studies, the mean internal diameters of the bodies of 40 NS-PTFE and 26 S-PTFE grafts were 11% and 10% greater than the manufacturer's specified sizes at a mean follow-up duration of 36 and 10 months respectively. CONCLUSIONS: These data reveal that a PTFE graft performs satisfactorily in the aortic position with minimal adverse clinical sequence over a 7.5 year period. Continued long term follow up data will determine the ultimate suitability of aortic PTFE grafts.