Surgery

The study was conducted to identify patient and procedural parameters that negatively impact the 30-day rates for stroke, death and transient ischemic attack (TIA) after carotid artery stenting (CAS) and that might be modified or further studied in future efforts to improve CAS. Methods: This was a retrospective investigation of a dual-center CAS database of 701 consecutive CAS patients (414 men; mean age, 72.4 ؎ 8.4). A subset of patient-related, lesion-related, or procedure-related variables (age >80, left sided lesion, symptomatic, nicotine abuse, hypertension, diabetes mellitus, other peripheral vascular disease, hypercholesterolemia, embolic protection devices usage, predilation, ulcerated lesion, echolucent plaque, restenosis after surgery) were analyzed for association with occurrence of stroke, death, or TIA <30 days after CAS. The odds ratio (OR) and 95% confidence interval (CI) and P value were calculated for each variable to predict adverse outcome. Results: The overall combined rate of stroke, death, and TIA within this database was 3.7% at 30 days. In the total population of 701 patients, only the OR of 2.7 for hypercholesterolemia (95% CI, 1.0 to 7.3; P ‫؍‬ .041) was found to be significant. Subgroup analysis of the 304 symptomatic patients (43%) showed that open-cell stent designs and concentric EPD designs yielded an OR of 4.1 (95% CI, 1.4 to 12, P ‫؍‬ .0136) and 3.3 (95% CI, 1.016 to 10, P ‫؍‬ .0525), respectively, for 30-day stroke/death/TIA within this database. Analysis of open-cell stent designs and concentric EPD designs in patients with echolucent lesions yielded an OR of 3.1 (95% CI,1.2 to 8.2, P ‫؍‬ .0343) and 3.7 (95% CI, 1.3 to 10, P ‫؍‬ .0174), respectively, for 30-day stroke/death/TIA. Conclusions: We conclude that increased analysis of device design variables may be necessary. Particularly in symptomatic patients or with echolucent lesions, closed-cell design and eccentric filters seem superior. Prospective investigation comparing open-cell vs closed-cell stents and eccentric vs concentric filter devices may be warranted. ( J Vasc Surg 2006; 44:725-30.)

Endovascular strategies for the treatment of critical infrageniculate peripheral arterial occlusive disease exist and are becoming the primary methodology for such lesions at many centers. Although technically feasible for experienced operators, the evidence to support this strategy for below the knee (BTK) interventions is still evolving. We studied the 6-month and 1-year outcomes of percutaneous transluminal angioplasty (PTA) alone, PTA with stenting, and excimer laser recanalization for BTK lesions in patients with critical limb ischemia.

Background. Recent studies found that edema, histology, and left ventricular diastolic compliance exhibit quantitative relationships in rats. Edema due to low osmolarity coronary perfusates increases myocardial water content and histologic edema score and decreases left ventricular filling. The present study examined effects of perfusate osmolarity and chemical composition on rat hearts.Methods. Arrested American Cancer Institute (ACI) rat hearts (4°C) were perfused with different cardioplegia solutions, including Plegisol (289 mOsm/L), dilute Plegisol (172 mOsm/L), Stanford solution (409 mOsm/L), and University of Wisconsin solution (315 mOsm/L). Controls had blood perfusion (310 mOsm/L). Postmortem left ventricular pressure-volume curves and myocardial water content were measured. After glutaraldehyde or formalin fixation, dehydration, and paraffin embedding, edema was graded subjectively.Results. Myocardial water content reflected perfusate osmolarity, being lowest in Stanford and University of Wisconsin solutions (p < 0.05 versus other groups) and highest in dilute Plegisol (p < 0.05). Left ventricular filling volumes were smallest in dilute Plegisol and Plegisol (p < 0.05). Osmolarity was not a major determinant of myocardial edema grade, which was highest with University of Wisconsin solution and dilute Plegisol (p < 0.05 versus other groups).Conclusions. Perfusate osmolarity determined myocardial water content and left ventricular filling volume. However, perfusate chemical composition influenced the histologic appearance of edema. Pathologic grading of edema can be influenced by factors other than osmolarity alone.

Background: Although aggressive endoluminal therapy for superficial femoral artery (SFA) occlusive disease is commonplace, the implications of diabetes mellitus (DM) on long-term outcomes in this population are unclear. We examined the consequences of endovascular treatment of the SFA in patients with and without DM. Methods: A database of patients undergoing endovascular treatment of the SFA between 1986 and 2005 was maintained. Three groups were defined: nondiabetic patients, those with non-insulin-dependent DM (NIDDM), and those with insulin-dependent DM (IDDM). Intention-to-treat analysis was performed. Results were standardized to TransAtlantic Inter-Society Consensus (TASC) and Society for Vascular Surgery criteria. Time-dependent outcomes were assessed with Kaplan-Meier survival analyses. Factor analyses were performed using a Cox proportional hazard model for timedependent variables. Data are presented as mean ؎ SD where appropriate. Results: Endovascular treatment (ie, balloon angioplasty ؎ adjuvant stenting in 38%) was initiated in 525 limbs in 437 patients (68% male; average age, 66 ؎ 14 years) for claudication failing conservative therapy or chronic critical limb ischemia (CLI). Of these, 50% were nondiabetic, 26% had NIDDM, and 24% had IDDM. Analyses were separated by those presenting with claudication (61%) and those presenting with CLI (39%). Among patients presenting with claudication, those with IDDM had significantly lower assisted primary patency (P < .01) and a higher incidence of restenosis (P ‫؍‬ .04). Patencies at 3 years for nondiabetic, NIDDM, and IDDM were 62%, 72%, and 54% (primary), and 81%, 86%, and 65% (assisted primary), respectively. Patency and restenosis rates were associated with lesion calcification, TASC D lesion categorization, and acute periprocedural occlusion. Among patients presenting with CLI, patency and restenosis rates were equivalent across all groups; however, limb salvage was significantly worse for both groups of diabetic patients compared with nondiabetic (NIDDM, P ‫؍‬ .01; IDDM, P ‫؍‬ .02). Reduction in limb salvage rates was associated with presence of tissue loss at presentation, end-stage renal disease, and progression of distal disease on follow-up. Conclusions: Endoluminal therapy for SFA occlusive disease yields lower assisted patency rates and higher restenosis rates for those patients presenting with claudication who have more advanced diabetes (ie, IDDM). Among those patients presenting with CLI, particularly those with tissue loss, limb salvage rates are lowered for the diabetic groups (NIDDM and IDDM) despite equivalent patency and restenosis rates. ( J Vasc Surg 2007;46:946-58.)

This study investigated changes in left ventricular (LV) geometry and systolic function after corrective surgery for atrial (ASD) and ventricular septal defects (VSD).Transesophageal LV short-axis echocardiograms were recorded before and after operative repair of ASD (n = 11) and VSD (n = 7). Preload was measured using LV end-diastolic area indexed for body surface area. Measurements of septal-freewall (D1) and anterior-posterior (D2) endocardial diameters were used to assess LV symmetry from D1/D2. Systolic indices included stroke area, area ejection fraction, and fractional shortening.Preload, stroke area, area ejection fraction, and fractional shortening of D1 increased after ASD repair but decreased after VSD repair (p < 0.05). End-diastolic symmetry increased after ASD closure and decreased after VSD closure (p < 0.05). Increases in stroke area and ejection fraction after ASD correction primarily reflected increased shortening of D1. A positive correlation was found overall between percent change in end-diastolic area (EDA) and percent change in area ejection fraction (r2 = 0.80, p < 0.0001, n = 18).Preload was the primary determinant of changes in LV function in this series of ASD and VSD repairs. Intraoperative changes in position of the interventricular septum affected systolic and diastolic LV symmetry and septal free wall shortening. Additional studies are needed to define changes in afterload and contractility as well as diastolic compliance and systolic mechanics.

Current recommendations for follow-up after endovascular repair of abdominal aortic aneurysms (EVAR) include yearly computed tomographic (CT) scans after the first year. We hypothesize that this is unnecessary for patients who have aneurysm sacs that are stable or shrinking at 1 year and no evidence of endoleak. To explore this hypothesis, we reviewed the records of all patients undergoing EVAR at our institution who were implanted with grafts that are currently commercially available and had a minimum of 18 months' follow-up. Of 415 patients who underwent EVAR over an 8-year period, 93 met the entry criteria. At a mean follow-up of approximately 3 years, secondary interventions were required in 13%, 39%, and 25% of patients undergoing EVAR with Zenith, AneuRx, and Excluder devices, respectively, and secondary interventions after the first year were required in 3%, 22%, and 8% of such grafts, respectively. Seventy-one patients (76%) had aneurysm sacs that were stable or shrinking at 1 year and no endoleak. Only two of these patients subsequently required reintervention. Both patients had AneuRx grafts, and both problems could have easily been identified without CT scanning. Our data support the hypothesis that patients who meet these criteria at 1 year are unlikely to have problems that cannot be identified by ultrasound and/or clinical evaluation alone and, thus, that CT scans are not necessary after this point, especially in patients with Zenith or reengineered Excluder devices.

While aggressive endoluminal therapy for superficial femoral artery (SFA) occlusive disease is commonplace, the implications of chronic kidney disease (CKD) on long-term outcomes in this population are unclear. We examined the consequences of endovascular treatment of the SFA in patients with and without varying stages of CKD. A database of patients undergoing endovascular treatment of the SFA between 1986 and 2007 was queried, and two groups were defined: estimated glomerular filtration rate (eGFR) ≤60 and >60 mL/min/1.73 cm2. Intention-to-treat analysis was performed. Results were standardized to TransAtlantic Inter-Society Consensus (TASC-II) and Society for Vascular Surgery criteria. Kaplan-Meier analyses were performed to assess time-dependent outcomes. Factor analyses were performed using a Cox proportional hazard model for time-dependent variables. Data are presented as mean ± standard deviation where appropriate. There were 525 limbs in 535 patients (68% male, average age 66 ± 14 years) that underwent endovascular treatment for claudication or chronic critical limb ischemia (51%). Patients with eGFR ≤60 were older and had significantly more coronary artery disease, congestive heart failure, diabetes mellitus, and hyperlipidemia. TASC-II lesion distribution was equivalent (37% for TASC-II C and D), but tibial runoff was significantly worse in the eGFR ≤60 group. In addition, there were more inflow and outflow interventions in the eGFR ≤60 group. In patients with claudication, there was no difference in patency or limb salvage between those with eGFR ≤60 and >60. In patients with critical limb ischemia, there was no difference in patency between those with eGFR ≤60 and >60. Limb salvage was worse in patients with eGFR ≤60 compared to eGFR >60. With respect to limb salvage, six factors were significantly associated with a reduction in rates: presence of tissue loss at presentation (relative risk [RR] = 6.45, p = 0.003), 0 or 1 vessel tibial runoff (RR = 2.56, p < 0.01), progression of distal disease noted in follow-up (RR = 4.62, p < 0.01), embolization at the initial intervention (RR = 2.70, p < 0.05), diabetes mellitus (RR = 3.71, p < 0.01), and a history of congestive heart disease (RR = 2.42, p < 0.01). Notable factors that were not significantly associated included lesion calcification (p = 0.64), TASC C or D lesion categorization (p = 0.99), acute occlusion at initial intervention (p = 0.40), and adjuvant stenting (p = 0.67). CKD does not impact the patency of SFA interventions. Limb salvage in patients with critical ischemia is significantly worse when the eGFR is ≤60 mL/min/1.73 cm2.

Background. To minimize decreases in left ventricular (LV) compliance immediately after rat heart transplantation, we tested several different methods of myocardial protection.Materials and methods. Five groups of ACI rat hearts (n = 6 each) were arrested by coronary perfusion with 5 ml of UW (University of Wisconsin), UW-BDM (UW with 2,3-butanedione monoxime), CU (Columbia University), or CU-BDM solution or by LV injection of potassium chloride and Ringer's lactate immersion (KCl/RL). After abdominal isografting and blood reperfusion for 15 min, transplanted hearts (TxH) were arrested and excised. Diastolic LV pressure-volume curves (LVPVCs) were correlated with myocardial water content (MWC). Native hearts (NH) were arrested identically to TxH and maintained at 4°C by immersion. LVPVCs were measured at 15-min intervals for 90 min.Results. In three of four pressure intervals at Time 0, normalized LV volume (LVV) was smaller (P < 0.05, ANOVA) in KCl/RL native hearts than in the four perfusion groups. LVV decreased significantly in NH after 45–75 min; LVV decreased similarly with time in all groups. In TxH, postarrest LVVs were higher with UW-BDM, CU-BDM, and CU than with UW or KCl/RL (P < 0.05, ANOVA). Expressing LVV of TxH as a percentage of NH, UW-BDM, CU, and CU-BDM provided qualitatively better diastolic properties than KCl/RL and UW.Conclusions. Thus rat LVPVCs can be improved after heart transplantation with alternative strategies of myocardial protection. KCl arrest decreases LV filling volume in this model and should be avoided.

The utility of open chest conductance (COND) ventriculography is limited by artifacts altering the relationship between COND and left ventricular (LV) volume. Pressure-COND loops often lean to the left during LV volume reduction by caval occlusion. Time varying alterations in the pericardial-LV contact area affect electrical coupling in the open chest during the cardiac cycle, producing COND artifacts. In this study, an open-mediastinum model was constructed. Components represented the LV, blood, pericardium, and thoracic contents. Varying Ventriculothoracic coupling was simulated by changing the volume of pericardial saline (0, 30, 60 ml). Raw dual field COND was repeatedly (n = 20) compared with volumes of normal saline from 60 to 120 ml at 5 ml intervals. Groups were compared by linear regression and repeated measures ANOVA. Artifacts significantly (p < 0.01) altered parallel COND, indicated by the y-intercept, with the exception of 0 versus 30 ml. The slope constant also changed significantly, with the exception of 30 versus 60 ml. These results suggest that variable pericardial-LV contact can cause time varying artifacts in COND in the open chest. Therefore, posterior insulation may reduce artifacts in COND ventriculography and should be tested for this effect. ASAIO Journal 1999; 45:64-68.

Objectives: Use of the heterotopic rat cardiac isograft model is limited by ventricular atrophy attributable to the left ventricle's non-working state. Previous studies indicate that increased left ventricular pressure-volume work minimizes atrophy. We used a simpler approach to increase ventricular work, imposing aortic regurgitation on the transplant. We hypothesized that this would prevent atrophy and preserve left ventricular compliance.

Background. Real-time measurement of left ventricular end-diastolic volume (LVEDV), combined with left ventricular end-diastolic pressure (LVEDP), would allow continuous measurement of intraoperative diastolic function. In pursuit of this goal, we examined stroke volume divided by ejection fraction for calculation of LVEDV sv/ef .

related myocardial edema. We have shown previously that myocardial edema is present clinically in cardiac allograft rejection 6 and that crystalloid coronary perfusion results in edema and predictable commensurate impairment of myocardial filling. The impaired left C ardiac transplantation is an accepted mode of therapy for end-stage heart disease; however, allograft rejection continues to be an obstacle to long-term survival. Recent studies have demonstrated the role of nitric oxide in allograft rejection, graft function, and Objective: Inhibition of inducible nitric oxide synthase (nitric oxide II) activity has been proposed as a method to attenuate capillary leak and edema during rejection of heterotopically transplanted rat hearts. Myocardial edema has previously been implicated in diastolic dysfunction during allograft rejection. Accordingly, we tested the hypothesis that inducible nitric oxide synthase inhibition with aminoguanidine would alleviate left ventricular stiffening and myocardial edema formation in 4-day heterotopic rat heart allografts.

Objective. We have found diastolic properties of the rat heart extremely sensitive to the method used to induce arrest. Accordingly, we sought to develop a reliable solution for measuring the LV pressurevolume relationship (LVPVR) in the rat.

Quantitative two-dimensional echocardiography (Q2-DE) may be used to detect intraoperative changes in left ventricular (LV) mass (M) and wall thickness (h). Potential causes of change in h include physiological redistribution of myocardium, myocardial edema, reactive hyperemia, and intramyocardial hemorrhage. Changes in h, in the absence of changes in LV shape and volume, generally indicate increased LVM. When changes in h are accompanied by changes in shape or volume, changes in LVM can only be detected by mathematical modeling, unless the direction of the observed changes is opposite that expected with physiological redistribution. Histological observations essential to understanding current mathematical models are presented and related to the inherent solid geometry. Technical considerations in determination of LV mass by Q2-DE are discussed. New procedures that alter LV volume and geometry, such as the Batista operation, defy modeling by conventional methods. Modeling techniques that allow an experimental approach to understanding LVM and h under such conditions are presented.

While aggressive endoluminal therapy for occlusive disease of the major branches of the arch of the aorta (brachiocephalic [BCA], left common carotid [LCCA], and left subclavian [LSCA] arteries) is commonplace, long-term outcomes in this population are unclear. We examined the long-term outcomes of endoluminal therapy for ostial aortic arch disease at a single tertiary referral academic medical center. A prospective database of patients undergoing endovascular treatment of aortic arch vessel atherosclerotic occlusive disease between 1990 and 2004 was maintained and retrospectively analyzed. Patients with stenotic ostial lesions of the major thoracic aorta branches were selected. Angiograms were reviewed in all cases to assess lesion characteristics. Patency was assessed by routine clinical and, in the LCCA and LSCA, duplex ultrasound follow-up at 1, 6, and 12 months postintervention and every 12 months thereafter.

Iliac arteriovenous (AV) fistula is rare after lumbar disk surgery. Traditionally, open repair through the arterial lumen was performed. We report endovascular exclusion of an iliac AV fistula in a 41-year-old woman 8 years after lumbar diskectomy. An angiogram showed an AV fistula connecting the right common iliac artery and vein. This was repaired with placement of two covered wall stents in the right common artery and external iliac artery, and embolization of the right internal iliac artery. Contrast medium-enhanced computed tomography scan at 5 months confirmed elimination of the AV fistula and right iliac artery patency. This technique should be considered in management of iliac AV fistulas. (J Vasc Surg 2003;37:1091-3.)

The classic approach to aortic graft infections involves complete excision of the graft material with remote reconstruction of the distal circulation. Certain patients may not be well suited for this approach for physiologic or anatomic reasons. This study was undertaken to determine the outcome of partial graft excision in selected patients with aortic graft infection who were not felt to be candidates for complete graft excision. Retrospective analysis of 30 consecutive patients treated with infected grafts arising from the aorta over the past 10 years was performed. Mean interval between graft placement and infection was 5.5 years. Complete graft excision with bypass via clean tissue planes was achieved in 15 patients (group A), and partial or complete graft salvage or in situ graft replacement was performed at the discretion of the surgeon in 15 patients (group B). Perioperative mortality occurred in eight subjects (27%), including six in group A (40%) and two in group B (13%; p = NS). Six patients (20%) developed recurrent infection following graft excision, two (13%) in group A and four (27%) in group B (p = NS).

Lens induction is a classic example of the tissue interactions that lead to cell specialization during early vertebrate development. Previous studies have shown that a large region of head ectoderm, but not trunk ectoderm, of 36 h (stage 10) chicken embryos retains the potential to form lenses and synthesize the protein δ-crystallin under some conditions. We have used polyacrylamide gel electrophoresis and fluorography to examine protein and glycoprotein synthesis in presumptive lens ectoderm and presumptive dorsal (trunk) epidermis to look for differentiation markers for these two regions prior to the appearance of δ-crystallin at 50 h. Although nearly all of the proteins incorporating3H-leucine were shared by presumptive lens ectoderm and trunk ectoderm, these two regions showed more dramatic differences in the incorporation of3H-sugars into glycoproteins. when non-lens head ectoderm that has a capacity for lens formation in vitro was labeled, a hybrid pattern of glycoprotein synthesis was discovered: glycoproteins found in either presumptive lens ectoderm or trunk ectoderm were oftentimes also found in other head ectoderm. Therefore, molecular markers have been identified for three regions of ectoderm committed to different fates (lens and skin), well before features of terminal differentiation begin to appear in the lens.