G.Richard Curl

Total excision and extra-anatomic bypass for aortic graft infection☆

Reports of high mortality and amputation rates following total excision and extra-anatomic bypass for aortic graft infection have prompted the use of alternate approaches including local antibiotics, partial resection, in situ revascularization, and graft excision without revascularization. Experience with aortic graft infection was reviewed to establish current morbidity and mortality rates and evaluate our bias in favor of total excision and extra-anatomic bypass. Aortic graft infection was identified in 32 patients, 8 with aortoenteric fistulas. The mean interval between graft placement and infection was 34 months. History of groin exposure (75%) or multiple prior vascular surgery (50%) was common. Clinical signs included fever and/or leukocytosis (23 patients), false aneurysm (9 patients), graft thrombosis (6 patients), groin infection (11 patients), and gastrointestinal hemorrhage (6 patients). Microbiologic data, available in 26 patients, demonstrated gram-positive organisms in 15 patients and gram-negative in 9. Multiple organisms were seen in 11 patients. Patients were treated by partial removal with (8 patients) or without (4 patients) revascularization or total removal with (18 patients) or without (2 patients) revascularization. Revascularization was by an extra-anatomic route, either simultaneous or staged. Overall morbidity/mortality was less in the revascularized groups (p = 0.01), while late complications were seen only after partial removal (p less than 0.01). The best results were found after total excision with revascularization. No patient in this group experienced late infection or amputation during a mean follow-up of 34 months (range: 1 to 168 months). Complications after total excision and extra-anatomic bypass for aortic graft infection are lower than generally appreciated. This approach should remain the standard to which other approaches are compared.

Aneurysmal change at or above the proximal anastomosis after infrarenal aortic grafting

We conducted a retrospective review of all patients undergoing repair of abdominal aortic aneurysm at or above the proximal anastomosis of a previous infrarenal aortic graft between 1986 and 1991. Infected grafts and patients with suprarenal aneurysms present at the time of the original graft were excluded. Twenty-one patients, 19 men and two women, were included. The original indication for surgery was aneurysm in 14 patients and occlusive disease in seven; the mean interval from initial surgery to presentation was 10 years (range, 3 to 23 years). Twelve lesions were anastomotic false aneurysms, and nine were true aneurysms beginning in the proximal juxta-anastomotic aorta. Fourteen patients had an asymptomatic abdominal mass. Seven patients had symptoms of acute expansion (three), rupture (three), or thrombosis (one). True aneurysm and symptomatic presentation were correlated with aneurysm as the original indication for surgery. Repair was accomplished by an interpositional graft in 13 and graft replacement in eight. Seven patients required suprarenal anastomosis or renal and visceral reconstruction. Five operative deaths (24%) occurred, including two of three patients with rupture (67%) and two of seven patients (28%) in the suprarenal group. The mortality rate for elective repair with an infrarenal anastomosis was 11%. Two additional late deaths occurred during the follow-up period.

Screening for asymptomatic deep vein thrombosis in surgical intensive care patients

PURPOSE To identify the presence of occult deep vein thrombosis (DVT) in surgical intensive care unit (SICU) patients and to avoid unnecessary screening, we reviewed our experience with routine duplex screening for DVT in SICU patients. METHODS Over a 24-month period, all patients who were admitted to an SICU with an anticipated length of stay greater than 36 hours were studied to determine the prevalence of risk factors for asymptomatic proximal DVT. Risk factors, demographics, and operative data were collected and analyzed with multilinear regression, t tests and chi 2 analysis. RESULTS There was a 7.5% prevalence of major DVT in the 294 patients studied. APACHE II scores (14.5 +/- 6.24 vs 10.3 +/- 3.15; p < 0.0001) and emergent procedures (45.5% vs 23.2%; p > 0.0344) were associated with DVT by multifactorial analysis. Age was significant by univariate analysis. An algorithm based on the presence of any one of the three risk factors identified (APACHE II score 12 or more; emergent procedures; or age 65 or greater) could be used to limit screening by 30% while achieving a 95.5% sensitivity for identification of proximal DVT. CONCLUSION Absence of all three risk factors indicates a very low risk for DVT (1.1%). Screening of SICU patients is indicated because of a high prevalence of asymptomatic disease. Patients who have proximal DVT require active therapy and not prophylaxis. Costs and resources may be contained by using the above risk factors as a filter for duplex screening.

Long-term follow-up of patients with early atherosclerosis

PURPOSE Patients with premature peripheral vascular disease may respond differently than their older counterparts. To determine the impact of early onset of atherosclerosis on outcome, we decided to compare a group of these patients with a group of patients with typical onset of atherosclerosis with regard to early complications, indications for intervention, site of disease at initial presentation (aortoiliac, infrainguinal, or cerebrovascular), and long-term outcomes (secondary revascularization, amputation, and death). METHOD All patients younger than 50 years old requiring operative intervention between 1987 and 1992 were retrospectively compared with a group of patients greater than 60 years old, randomly selected from patients who underwent operation during the same time period. Patients were evaluated and compared for indications, risk factors, and early and late outcomes. RESULTS Patients with early onset atherosclerosis at the aortoiliac or infrainguinal level had a higher late amputation rate (17% versus 3.9%, p = 0.02) and poorer overall outcome than their older cohorts. Patients with cerebrovascular disease in both cohorts had similarly good prognoses. CONCLUSION Aortoiliac or infrainguinal disease diagnosed in patients less than 50 years of age portends a poorer outcome than does similar disease in an older patient population.

Stent-Related Iliac Artery and Iliac Vein Infections: Two Unreported Presentations and Review of the Literature

Purpose: To discuss the presentation, diagnosis, and treatment of stent-related infections on the basis of 2 new cases and historical review. Case Reports: Two previously unreported cases of vascular stent infection are presented with a summary of cases from the literature. One case involved an iliac artery stent infection secondary to a remote bacteremia 6 months after stent placement. The other case was an early iliac vein stent infection, a previously unreported site of this complication. Both cases were diagnosed by use of computed tomography and were treated surgically after medical management failed. Both patients survived. Conclusions: A high index of suspicion is necessary for the diagnosis of stent infections, and an aggressive treatment is usually necessary for survival. Prophylactic antibiotics should definitely be considered in cases involving repeat interventions and prolonged catheterization, as well as before bacteremia-inducing therapies.

A Prospective, Randomized, Blinded, and Placebo-controlled Trial of Intraoperative Intra-arterial Urokinase Infusion During Lower Extremity Revascularization: Regional and Systemic Effects

ObjectiveThis study was designed to evaluate the safety and regional and systemic effects of three doses of urokinase (UK) infused into the distal arterial circulation during routine operative lower extremity revascularization. MethodsOne hundred thirty-four patients were prospectively randomized to receive one of three bolus doses of UK (125,000, 250,000, or 500,000 U) or placebo (saline) infused into the distal circulation before lower extremity bypass for chronic limb ischemia. Regional (femoral vein) and systemic (arm) blood was sampled before drug infusion, prereperfusion, and postreperfusion, and systemic blood samples were obtained 2 hours postreperfusion. Assays evaluated plasma levels of fibrinogen, fibrin(ogen) degradation products (FDP), fibrin breakdown products (D-dimer and fragment B-β 15–42), and plasminogen. Patients were monitored for clinically evident bleeding complications. The Wilcoxon rank-sum test was used to compare different drug doses with the placebo. ResultsIntraoperative bolus UK infusions produced no significant fibrinogen breakdown compared with placebo. There was a dose-related decline in plasminogen levels, which became significant at a dose of 500,000 U of UK (p < 0.001). There were dose-related increases in plasma FDP, which became significant at dose of 250,000 and 500,000 U (p≤0.005), and in plasma D-dimer, which were significant at all UK doses (p < 0.001). The changes in plasma fibrinogen and markers of fibrin breakdown were similar in the regional and systemic circulations. There was no increase in operative blood loss, blood replaced, or wound hematoma formation. There was an unexplained increased mortality in the placebo group (12.1% vs. 2.0%1 p = 0.033). ConclusionsIntraoperative bolus UK infusion is safe, with no significant fibrinogen depletion or increased operative blood loss or wound hematoma formation. Dose-related plasminogen activation resulted in significant breakdown in cross-linked fibrin in the distal circulation. Intraoperative bolus UK infusion may be valuable as an adjunct in patients with chronic occlusive disease who are undergoing revascularization. Detailed randomized studies are indicated to establish clinical efficacy.

A retrospective review of basilic and cephalic vein-based fistulas

This study compares outcomes of basilic and cephalic vein fistulas for hemodialysis. A retrospective review of arteriovenous fistulas in a university hospital system was performed using charts and hemodialysis records. Patency and demographic data were assessed with life table analysis. One hundred fifty-six patients (88 males; 68 females) underwent creation of 172 autogenous fistulas (mean age 61 years; mean follow-up 78 weeks). There were 101 basilic vein transpositions and 71 cephalic vein fistulas. Primary patency did not differ significantly, while assisted primary patency was significantly better for basilic vein fistulas at one year (73% versus 53%: P = 0.024). Secondary patency was significantly better for basilic fistulas through three years (58% versus 52%; P = 0.027). Primary failure (thrombosis before access or failed maturation) was significantly higher for cephalic than basilic fistulas (28% versus 13%; P = 0.01). Maturation time, usage time and complications were not significantly significant. Thirty-three (33%) basilic vein-based fistulas and 12 (17%) cephalic vein fistulas required revision during follow-up. Basilic vein-based fistulas perform as well as or better than cephalic vein-based fistulas in terms of patency, maturation time, and usage time and complication rates, though requiring more re-interventions.

Utility of an oral examination in a surgical clerkship

To evaluate the utility of the oral examination in a surgical clerkship, we designed a prospective and randomized study to relate the subjective impressions of experienced examiners with an objective measure of cognitive knowledge. The examiners were asked to score the students performance as honors, high satisfactory, satisfactory, or unsatisfactory, according to their subjective impression of the students ability. Student performance was grouped according to oral examination performance. The cognitive performance in the honors group was significantly better than that of the other groups (Students t-test, p = 0.05). There was a significant difference in cognitive performance for oral examination groups throughout the rotations (analysis of variance, p = 0.000; Kruskal Wallis, p = 0.05). The oral examination is useful to identify a high level of cognitive achievement but cannot discriminate between groups of median to low competence. It should be used for educational feedback, career counseling, residency recommendations, and professional development.

Factors that affect cost and clinical outcome of endovascular aortic repair for abdominal aortic aneurysm

Objective: This study evaluated the effect of indication for use (IFU), additional graft components, and percutaneous closure of endovascular aortic repair (PEVAR) on clinical outcomes and cost of endovascular aortic repair (EVAR). Methods: Clinical and financial data were obtained for all elective EVARs completed at a university‐affiliated medical center between January 2012 and June 2013. Data were analyzed by χ2, Student t‐test for independent samples, and Kaplan‐Meier survival. Results: There were 67 elective EVARs. Additional cuffs/extensions were used in 37%, increasing the baseline graft cost by 36% (P < .001), total costs by 20% (P < .001), and negatively affecting the contribution margin. Aortic neck IFU (P = .02), failure of the index graft to seal the neck (P = .02), and need for an additional cuff (P = .008) were related to the need for reintervention for type Ia endoleak for graft B (Excluder; W. L. Gore and Associates, Flagstaff, Ariz), whereas limb IFU was related to the need for additional limb extension for graft A (Powerlink; Endologix, Irvine, Calif; P < .001). Limb extension (P = .06) and failure of the index graft to provide an adequate seal (P < .001) were associated with reintervention for type Ib endoleak. Reintervention‐free rates at 24 months were 96% for graft A and 94% for graft B (P =.54), but different patterns in reintervention emerged: graft A required reoperation early (<2 months) then stabilized; graft B did not require reintervention until 24 months, but rates increased substantially by 25 months. PEVAR was attempted in 61 (91%): 49 (73%) bilaterally, 7 (10%) unilaterally, and 5 (8%) failed. The mean number of closure devices was four (range, 1–9):

The thrombosed prosthetic graft is a risk for infection of an adjacent graft

1000 (3.5% of total cost). Bilateral PEVAR was associated with shorter operating time than unilateral PEVAR/failed PEVAR (P < .001) and lower operating room use costs (P = .005) and total hospital costs (P = .003) than failed PEVAR. The contribution margin was higher for bilateral PEVAR than unilateral PEVAR/failed PEVAR (P = .005). Patients with bilateral PEVAR and unilateral PEVAR were more often discharged on postoperative day 1 than those with failed PEVAR (P = .002). Hospital length of stay (P = .49), operating room duration (P = .31), and total costs (P = .72) were similar for unsuccessful PEVAR and EVAR completed with cutdown. Conclusions: Higher rates of reintervention occurred when EVAR was performed outside of IFU guidelines or when additional components were needed. Additions raised graft costs significantly above baseline. Notable differences in graft performance in complex anatomy and varied patterns of reoperation could be useful in the graft selection process to improve outcome and contain costs. Bilateral PEVAR was associated with lower costs and postoperative day 1 discharge. Attempting PEVAR may be reasonable unless there is serious concern for failure.