Objective: The objective of this study was to evaluate the learning curve for fenestrated endovascular aortic aneurysm repair (FEVAR).Methods: Data were collected prospectively on all FEVAR procedures conducted by a single surgeon between June 2007 and January 2015. During the study period, 136 FEVARs were performed, and this experience was divided into four quartiles each consisting of 34 cases. Clinical outcomes evaluated included perioperative death and major complications. Process outcomes included length of procedure, fluoroscopy time, contrast material use, estimated blood loss, and intensive care unit length of stay.Results: During the study period, there was a statistically significant increase in the complexity of cases as evidenced by an increase in the proportion of cases with two or more fenestrations from 52.9% in the first quartile to 88.2% in the fourth quartile (P =.001). Despite this, there was a steady decrease in the proportion of patients suffering perioperative death or major complications from 23.5% in the first quartile to 8.8% in the fourth quartile. After adjustment for potential confounding factors, the odds of death or major complication were cut by 52.4% per quartile increase (95% confidence interval [CI], 7.8%-75.5%; P =.028). In addition, among cases with two or more fenestrations, geometric mean length of procedure was reduced from 223.8 minutes in the first quartile to 149.6 minutes in the fourth quartile, and geometric mean fluoroscopy time was reduced from 58.6 minutes in the first quartile to 31.5 minutes in the fourth quartile. After adjustment, there was an estimated 9.9% reduction in geometric mean procedure length per quartile increase (95% CI, 3.5%-15.9%; P =.003) and a 17.6% reduction in geometric mean fluoroscopy time per quartile increase (95% CI, 10.9%-23.8%; P <.0001).Conclusions: Despite an increase in case complexity, there was evidence for significant improvement in important clinical and process outcomes during the study period. We believe that much of this improvement was attributable to several key advances in the FEVAR procedure that were instituted during the study period and are discussed herein.

Learning curve effects (LCEs) for complex surgical procedures have been reported. Fenestrated endovascular aneurysm repair (FEVAR) represents a complex endovascular procedure and no good data describe the case volume required to designate “expertise.” Data were collected prospectively on all FEVAR procedures between June 2007 and January 2015 and included continuous variables: demographics, length of procedure (LOP), fluoroscopy time (FT), contrast usage (CON), estimated blood loss (EBL) and intensive care unit (ICU) and hospital lengths of stay; and dichotomous variables: perioperative death and major complications. Lowess smoothing was used to assess the underlying shape of trends between continuous variables and cumulative case experience, and these curves were stratified based on number of fenestrations (FENS) per case. During the study period, 137 FEVARS were performed. Evidence for a LCE was demonstrated in regard to LOP with FEVAR involving three FENS (P = .0001). In this group, LOP was halved from ∼300 to 150 minutes over the study period, which correlated precisely with significant procedural changes. In regard to FT, a LCE was demonstrated for two and three FEN cases (60 to 20 minutes [P = .006] and 75 to 25 minutes [P < .001]) over the study period. The LCE for CON was significant for the first 60 cases (P = .02) in all groups but then showed no change. There was no LCE for EBL or ICU LOS for any group. Three FEN cases increased from 29% to 72% of the total cohort over the study period. LOP, FT, and CON for three FEN cases are depicted in the Fig. Overall morbidity and mortality were not different over the study period. There was evidence for a LCE for LOP, FT, and CON, which was strongest for three FEN cases. The shape of the learning curve was “step-like” and appeared to be driven by specific procedural improvements rather than by cumulative experience. Our findings suggest that adoption of these procedural improvements will steepen the learning curve (ie, allow rapid improvement) for surgeons performing FEVAR in the future.

Several scoring systems for predicting mortality in patients with ruptured abdominal aortic aneurysms (rAAA) in the endovascular era have been derived. However, all of these scores include intraoperative variables that limit their utility in preoperative planning and patient counseling. The purpose of this study was to develop and validate a practical mortality risk score using only preoperative variables and compare it with other previously published scoring criteria. Data on all patients with rAAA presenting between January 1, 2002, and October 31, 2013, were collected. Univariate logistic regression was used to identify important predictors of mortality. Multiple logistic regression analysis was used to select a subset of four of these variables and combine their values into a single predictor of rAAA mortality. The predictor’s accuracy was compared with previously published algorithms. A total of 303 patients presented during the study period. Fifteen patients died in the emergency department, en route to surgery, or after choosing comfort care. Overall, 30-day mortality was 54% for patients undergoing open rAAA repair and 22% for those undergoing endovascular rAAA repair. Preoperative variables most predictive of mortality were preoperative systolic blood pressure <70 mm Hg (odds ratio [OR], 2.7; P < .05), pH <7.2 (OR, 2.6; P < .05), age <76 years (OR, 2.1; P < .05), and creatinine >2 (OR, 3.7; P < .05). Patient stratification according to the preoperative rAAA mortality risk score (range, 0-4) accurately predicted mortality and identified those at low-risk and high-risk for death. While the Vascular Study Group of New England score, Glasgow aneurysm score, and Edinburg score were validated in our contemporary data set, our preoperative risk score was most predictive with area under the curve of 0.67. Existing scoring systems predict mortality after rAAA repair in our cohort but rely on intraoperative variables. Our rAAA mortality risk score is based on four variables readily assessed preoperatively, allows accurate prediction of in-hospital mortality after repair of rAAAs in the EVAR-first era, and does so more accurately than those previously described.

Endovascular reconstruction of the femoral and popliteal arteries is replacing femoral-popliteal bypass. This is made possible by subintimal recanalization to manage long chronic total occlusions. Re-entry into the true lumen is the most challenging step in this process. This article summarizes the techniques for re-entry into the true lumen in the superficial femoral and above- and below-the-knee popliteal arteries.

The purpose of carotid angioplasty and stent (CAS) is stroke prevention. Large trials have been conducted or are underway to understand the results of CAS. However, two significant questions remain: (1) What are the long-term results, beyond the reports of 2 to 4 years? (2) Do the results of major trials correlate with similar results in the community at large? The purpose of this study is twofold: to evaluate the long-term results of CAS with respect to stroke-free survival, re-stenosis, and reintervention; and, to assess the overall result of CAS in a community setting. Over a 9-year period (2002-2010), we used CAS as a treatment for significant carotid stenosis in 162 procedures in 150 patients. In most of the patients, there was one or more anatomic or physiological indication for CAS due to high-risk status for carotid endarterectomy. After CAS, patients were followed with surveillance duplex scan in a certified vascular laboratory at 1 month, 6 months, 1 year, and annually thereafter. Peak systolic velocity (PSV) >200 cm/seconds was considered to be a re-stenosis of >50% and PSV >300 cm/seconds was considered to be >70% re-stenosis. Repeat interventions were performed at the discretion of the treating surgeon. The risk of perioperative stroke was 3.1% and death was 0.6%. Mean follow-up was 2.6 years with a range of 0 to 8.9 years. One hundred twenty of the procedures (74%) had a follow-up of at least 1 year. Stroke-free survival at 1, 3, and 5 years was 91%, 70%, and 53%, respectively. Freedom from all causes of stroke was 96% at 1 year, 95% at 3 years, and 92% at 5 years. Re-stenosis of 50% or more occurred in 4% at 1 year, 8% at 3 years, and 8% at 5 years. Re-stenosis of 70% or more occurred in 2% at 1 year, 6% at 3 years, and 6% at 5 years. Only three (1.9%) of the index procedures required re-treatment. None of the patients with recurrent stenosis presented with neurologic symptoms. None of the patients died of stroke during long-term follow-up. Long-term stroke-free survival was diminished in this population at high risk for carotid surgery. The rates of re-stenosis, reintervention, and stroke from any cause were acceptable after CAS. These data suggest that CAS can be performed in a community setting with acceptable long-term durability and stroke prevention.

Objective: The optimal treatment for hemodynamically significant infrainguinal vein bypass graft stenosis is not known. This study compares three options as first choice for the revision of failing infrainguinal vein grafts: cutting balloon angioplasty (CBA), standard percutaneous transluminal balloon angioplasty (PTA), and open surgical revision (OS).Methods. Infrainguinal vein bypass graft lesions treated in a single institution during a 12-year period were evaluated. Of these, 161 lesions in 124 infrainguinal bypasses (101 patients) were treated with OS (n = 42), PTA (n = 57), or CBA (n = 62). The initial indication for the bypass in these patients was limb salvage in 73% and claudication in 27%. The primary outcome of interest was the development of vein graft occlusion or significant stenosis (>= 70%) as detected by surveillance duplex ultrasound scanning or arteriography some time after repair.Results: The stenosis-free patency rates at 48 months for OS, CBA, and PTA were 74%, 62%, and 34%, respectively. PTA was associated with an increased risk of treatment failure compared with both OS (hazard ratio [HR], 3.9; P < .0001) and CBA (HR, 3.1; P < .0001). There was no significant difference between OS and CBA (HR, 1.3 for CBA vs OS, P = .6). Pseudoaneurysms developed in two CBA patients. One ruptured and required interposition graft, and one was monitored.Conclusion: Cutting balloon angioplasty is a reasonable, initial treatment for infrainguinal vein graft stenosis in most patients. It is a safe, minimally invasive, outpatient procedure with patency rates that are comparable to OS and superior to PTA.

Chapter 4 Essential Operating Room Equipment, Personnel, and Catheter Inventory for Endovascular Repair of Abdominal Aortic Aneurysms Peter A. Schneider MD, Peter A. Schneider MDSearch for more papers by this authorMichael T. Caps MD, MPH, Michael T. Caps MD, MPHSearch for more papers by this author Peter A. Schneider MD, Peter A. Schneider MDSearch for more papers by this authorMichael T. Caps MD, MPH, Michael T. Caps MD, MPHSearch for more papers by this author Book Editor(s):Albert G. Hakaim MD, Albert G. Hakaim MD Consultant, Section of Vascular Surgery and Director, Endovascular Surgery, Mayo Clinic, Jacksonville, Florida; Associate Professor of Surgery, Mayo Clinic College of Medicine, Rochester, MinnesotaSearch for more papers by this author First published: 01 January 2006 https://doi.org/10.1002/9780470753156.ch5 AboutPDFPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShareShare a linkShare onFacebookTwitterLinked InRedditWechat Summary This chapter contains section titled: Introduction Personnel involved in endovascular repair of abdominal aortic aneurysms Operating room equipment Endovascular accessories and catheter inventory Conclusion Current Endovascular Treatment of Abdominal Aortic Aneurysms RelatedInformation

Objective: Carotid arteriography (CA) is an important method of assessing carotid artery occlusive disease and is the best method of planning for carotid angioplasty and stent placement (CAS). This study compared the results of CA performed by vascular surgeons in a contemporary series against widely recognized interdisciplinary quality standards for this procedure. Although many vascular surgeons perform CA, there is a paucity of data about its safety, efficacy, and compliance with quality standards in vascular practice. The importance of quality CA will likely increase as CAS emerges to assume a broader clinical role.Method: Carotid arteriograms performed by seven vascular surgeons at three institutions from September 2000 to May 2004 were reviewed. These results were compared with quality standards for the performance of CA.Results. Five hundred three carotid arteriograms were performed over 45 months. Indications for the procedure were extracranial cerebrovascular disease (86%), trauma (5%), and other conditions (9%). Indications for the procedure were appropriate in 100% of patients (as determined by guidelines document) and exceeded the recommended standard of appropriate indications in 99%. All procedures successfully provided the information required, exceeding the threshold of 98% for procedural success. Reversible neurologic deficits occurred in 0.6% (two transient ischemic attacks and one stroke) compared with the threshold of 2.5%. A permanent neurologic deficit occurred in 0.2% (1 patient) compared with the published guideline of 1% after carotid arteriography. Major non-neurologic complications occurred in 1.2% (6 patients), less than the standard of 2.0%.Conclusions. The safety and efficacy of a contemporary series of CA performed in vascular surgery practice compared favorably with recognized interdisciplinary quality standards for this procedure. Ensuring safe and effective CA is likely to support the successful growth of CAS as a treatment option.

Carotid angioplasty and stenting requires delivery of therapy through a sheath rather than open vascular access. Safe and successful sheath delivery facilitates the carotid angioplasty and stenting procedure and depends upon an ability to assess the aortic arch, catheterize its branches, perform remote access guidewire-catheter manipulation, and place a sheath.

The practice of endovascular is significantly enhanced by the use of a programmatic approach. Our goal as vascular specialists is to integrate endovascular techniques and concepts into vascular practice in the same way that we have integrated the medical and perioperative management of vascular patients into clinical care. In the not too distant future, the concept of vascular surgery is not likely to be independently functional. The most effective vascular specialists will be those who provide a full spectrum of management options that includes prevention, medical management, endovascular therapy, and open surgery; striving for the seamless care of patients with vascular problems. Vascular disease management appears to be approaching a stage in which endovascular will be the treatment of choice for most situations that require mechanical intervention, with open reserved for endovascular failures and those patients with the absolute worst disease morphology. Endovascular techniques have dramatically influenced the care of disease in every vascular bed. The opportunity to relieve suffering, reduce morbidity, and treat threatening illness with minimally invasive approaches is a privilege.

INTRODUCTION:There are no published reports on the association between ethnicity and outcome after aortoiliac stent grafting to treat aneurismal disease. Because Hawaii is a state with an ethnically diverse population, we conducted a retrospective study to examine this potential association. We hypothesized that individuals of Asian ancestry may have higher complication rates after endovascular repair compared with non-Asians. METHODS:All endovascular devices placed to treat aneurysm disease from 1996 to 2003 were evaluated in two institutions. The association between ethnicity and access-related and device-related complications, both periprocedural and delayed, was examined with logistic regression analysis. RESULTS:Ninety-two aortoiliac endografts were placed during the study period, including 87 in patients with abdominal aortic aneurysms with or without iliac aneurysm disease, and five patients with isolated iliac artery aneurysms. Forty-four percent of patients were categorized as Asian, 39% as white, 16% as Pacific Islander, and 1% as African American. Access-related and device-related complications (ADRCs) occurred in 11 of 92 (12%) of these patients. The following parameters were significantly associated with ADRCs: Asian ethnicity (P =.015), age greater than 80 years (P =.02), and external iliac diameter smaller than 7.5 mm (P =.01). Asian patients were more likely to have experienced ADRCs than were non-Asian patients (odds ratio, 7.3; 95% confidence interval, 1.5-35.8; P =.015). Asians also had smaller external iliac artery diameters (P =.0003) and more tortuous iliac arteries (P =.03) compared with non-Asians. After adjusting for iliac artery diameter and tortuosity, the association between Asian ethnicity and ARDCs became nonsignificant (P =.074), which suggests that the association between race and complications may be at least in part due to small and tortuous iliac arteries. There was no association between age, gender, or ethnicity and postoperative detection of endoleak. CONCLUSION:Our data indicate that individuals of Asian ancestry are far more likely to experience adverse access-related and device-related complications after aortoiliac stent grafting than are non-Asians. We found that this association is at least partly attributable to the smaller and more tortuous iliac arteries in persons of Asian ancestry.

BACKGROUND:Although epidemiologic studies of the general population have demonstrated a deficit of blood group O among patients with deep venous thrombosis (DVT), few studies have evaluated the importance of blood group in high-risk patients. The purpose of this study was to evaluate the importance of ABO blood group as a thrombotic risk factor in injured patients. METHODS:Injured patients with a discharge diagnosis of DVT were identified from an institutional trauma registry and compared with control patients matched for age and Injury Severity Score. ABO blood types of patients and controls were obtained from the regional blood center database. RESULTS:Three hundred forty-three case-control pairs were identified from a total of 401 consecutive cases of DVT. Blunt injury was the predominant mechanism of injury, accounting for 90.4% of cases. Chest (p = 0.01) and extremity (p < 0.001) Abbreviated Injury Scale scores were independent predictors of DVT. However, there was no significant difference in blood group distribution or the A to O ratio between patients with and without DVT. For non-type O patients, the odds ratio for developing DVT was 1.1 (95% confidence interval, 0.8-1.5; p = 0.5) in comparison with type O patients. CONCLUSION:These data do not support a clinically relevant association between blood type and DVT in trauma patients. Injury-associated derangements of coagulation may be more important than any hypercoagulability related to blood type in this population.

Objective. The study's aim was to evaluate access patency and incidence of revisions in patients initiating hemodialysis and to determine differences in access performance by type of access among patient subgroups.Methods. The study used data from the United States Renal Data System Dialysis Morbidity and Mortality Study Wave 2, which contained a random sample of dialysis patients initiating dialysis in 1996 and early 1997. Failures and revisions were evaluated among 2247 newly placed hemodialysis accesses by using Cox proportional hazards regression model and Poisson regression. Primary and secondary patency rates were estimated using the Kaplan-Meier method.Results. Fifteen hundred seventy-four prosthetic grafts, 492 simple autogenous fistulas, and 181 venous transposition fistulas were available for evaluation. Prosthetic grafts had a 41% greater risk of primary failure compared with simple fistulas (relative risk, 1.41; 95% CI, 1.22-1.64; P<.001) and a 91% higher incidence of revision (relative risk, 1.91; 95% CI, 1.60-2.28; P<.001). At 2 years, autogenous fistulas demonstrated superior primary patency (39.8% versus 24.6%, P<.001) and equivalent secondary patency (64.3% versus 59.5%, P=.24) compared with prosthetic grafts. When compared with simple fistulas, vein transpositions demonstrated equivalent secondary patency at 2 years (61.5% versus 64.3%, P=.43) but inferior primary patency (27.7% versus 39.8%, P=.008) and had a 32% increased incidence of revision (P=.04). Autogenous fistulas had superior primary patency compared with prosthetic grafts in all patient subgroups except for patients with previously failed access. Vein transpositions showed the greatest benefit in terms of patency and incidence of revision in women and in patients with previously failed access.Conclusions. The preferential placement of autogenous fistulas may increase primary patency and decrease the incidence of revisions. Vein transpositions had similar secondary patency compared with simple fistulas, but required more revisions. The greatest benefit of a vein transposition fistula was seen in women and in patients with a history of access failure.

PURPOSEThe purpose of this study was to evaluate the results of combining intraoperative balloon angioplasty (IBA) of the superficial femoral artery (SFA) with distal bypass graft originating from the popliteal artery as a method of lower extremity revascularization in diabetic patients with gangrene.METHODSAmong 380 infrainguinal bypass grafts performed over a 6-year period, there were 110 reversed saphenous vein bypass grafts to the tibial or pedal arteries to treat diabetic patients with gangrene. Diffuse infrainguinal disease was treated with femoral-distal bypass graft (long; n = 46). Popliteal-distal bypass graft was performed when the inflow femoral artery was not significantly diseased (short; n = 52). Focal SFA stenosis and severe infrageniculate disease were treated with combined IBA of the SFA and distal bypass graft originating from the popliteal artery (combined; n = 12). Follow-up was performed with duplex scan surveillance of both the bypass graft and IBA sites. Treatment groups were compared with life-table analysis.RESULTSThere were no perioperative graft failures or amputations. The perioperative mortality rate was 1% (1 of 110). The 2-year primary patency rates were similar in the three groups: 72% in the long bypass graft group, 82% in the short bypass graft group, and 76% in the combined group (P =.8, log-rank test). SFA IBA sites developed recurrent stenosis in two patients, at 7 and 48 months; both were detected with surveillance and treated with percutaneous transluminal balloon angioplasty. The overall 5-year rate of primary patency was 63%, secondary patency was 78%, limb salvage was 81%, and survival was 35%. There were no significant differences among the three treatment groups with respect to these outcomes.CONCLUSIONResults with the combined procedure were similar to those achieved with either femoral-distal bypass graft or popliteal-distal bypass graft without SFA IBA. These data suggest that IBA of the inflow SFA may be combined with popliteal to distal bypass graft and that this technique is a reasonable alternative to longer, femoral-origin bypass graft in selected diabetic patients with gangrene.

PURPOSE The safety and efficacy of percutaneous transluminal intervention for renal artery stenosis is improving. This study evaluates the immediate and long-term anatomic and functional outcomes of percutaneous transluminal angioplasty and stenting for atherosclerotic renal artery stenosis in a Veterans Affairs population. METHODS We performed a retrospective analysis of records from patients who underwent renal artery angioplasty with or without stenting at the Veterans Affairs Puget Sound Health Care System between January 1990 and June 1999. Indications for intervention included hypertension (78%) and rising serum creatinine (78%). Seventy-six patients (74 men, average age of 67 years, range 42-83 years) underwent 88 attempted interventions. Seventy-two percent of contralateral kidneys had significant disease (47% had a >60% stenosis; 16% were nonfunctioning or absent). RESULTS Of the 88 planned interventions, 86 were successfully performed with placement of 46 stents (52%). Technical success (defined by <30% residual stenosis) was achieved in 78 vessels (89%). The procedure-related complication rate was 5%. Patient mortality by life table analysis was 49% at 5 years. Assisted primary patency rate at 5 years was 100%. Primary and secondary restenosis rates were 37% +/- 8% and 31% +/- 8% at 5 years, respectively. Sixty-eight percent of patients treated for hypertension demonstrated clinical benefit (improved or cured hypertension). This clinical benefit was maintained in 52% of the patients at 5 years, as measured by life table analysis. Serum creatinine was lowered or maintained in 88% of the patients, but this clinical benefit was only maintained in 25% of patients at 5 years. CONCLUSIONS Transluminal intervention for clinically symptomatic atherosclerotic renal artery stenosis is technically successful and safe. There are excellent assisted-patency and low restenosis rates. There is immediate clinical benefit for most patients, as evidenced by improved control of hypertension and preservation of renal function. However, within 5 years the benefit is not maintained for either hypertension (50%) or renal function (20%). Therefore, although technically successful, functional outcomes after endoluminal intervention are not maintained in the long term.

BACKGROUND:The aim of this study was to evaluate the determinants of access patency and revision, including the effects of reducing the placement of prosthetic hemodialysis access.METHODS:A retrospective cohort study of all hemodialysis accesses placed at the Veteran's Administration Puget Sound Health Care System between 1992 and 1999 was conducted. A policy was instituted in 1996 that maximized the use of autogenous hemodialysis access. The impacts of the policy change, demographics, and comorbid factors on access type and patency, were examined. Primary and secondary patency rates were examined using the Kaplan--Meier method, and factors associated with failure and revision were examined using Cox proportional hazard models and Poisson regression.RESULTS:During the study, 104 accesses (61 prosthetic grafts and 43 autogenous fistulas) were placed prior to 1996, and 118 (31 prosthetic grafts and 87 autogenous fistulas) were placed after 1996. There was a significant increase in autogenous fistulas placed after 1996 (87 out of 118) compared with before 1996 (43 out of 104, P < 0.001). At one year, autogenous fistulas demonstrated superior primary patency (56 vs. 36%, P = 0.001) and secondary patency (72 vs. 58%, P = 0.003) compared with prosthetic grafts. After adjustment for age, race, side of access placement, and history of prior access placement, patients with a prosthetic graft were estimated to experience a 78% increase in the risk of primary access failure when compared with similar patients having an autogenous access [adjusted relative risk (aRR) = 1.78, 95% CI 1.21--2.62, P = 0.003)]. Similarly, the adjusted relative risk of secondary access failure for comparing prosthetic grafts with autogenous fistulas was estimated to be 2.21 (95% CI 1.38--3.54, P = 0.001). The adjusted risk of access revision was 2.89-fold higher for prosthetic grafts than for autogenous fistulas (95% CI 1.88--4.44, P < 0.001).CONCLUSIONS:Autogenous conduits demonstrated superior performance when compared with prosthetic grafts in terms of primary and secondary patency and number of revisions. A policy emphasizing the preferential placement of autogenous fistulas over prosthetic grafts may result in improved patency and a reduction in the number of procedures required to maintain dialysis access patency.

OBJECTIVE:The objective of this study was to assess the prognostic value of hemodynamic parameters measured with duplex ultrasound scan, together with other important graft and patient characteristics, in predicting lower extremity vein graft thrombosis.METHODS:A total of 165 lower extremity vein grafts were entered prospectively into a postoperative duplex ultrasound scan surveillance program with examinations performed at 1, 2, 3, 4, 6, 9, 12, 18, and 24 months, and annually thereafter. Duplex scan-derived blood flow velocity measurements were recorded at 1562 patient visits over 7 years. Graft patency was determined after each visit, and an analysis of factors predictive of vein graft thrombosis was performed with Poisson regression.RESULTS:Thirty-two episodes of first-time graft thrombosis occurred, 23 of which were permanent. One-, 3-, and 5-year secondary graft patency rates were 90%, 86%, and 79%, respectively. In multivariate analyses, duplex scan velocity measurements predictive of lower extremity graft thrombosis included the maximum velocity ratio (Vr) in association with a graft stenosis and the mean graft peak systolic velocity (MGV) within nonstenotic portions of the body of the graft. The incidence of graft thrombosis among grafts without inflow/outflow stenoses, with Vr less than 3.5, and with MGV 50 cm/s or more, was 2.9% per year. Incidence rates were considerably higher among grafts with a of Vr of 3.5 or more (incidence rate ratio = 7.0; 95% CI, 3.4-14.6) or an MGV less than 50 cm/s (incidence rate ratio = 6.5; 95% CI, 3.3-13.1). In grafts without identifiable inflow, outflow, or graft stenoses, there was no association between MGV and the risk of graft thrombosis.CONCLUSION:Duplex scan velocity measurements are valid predictors of impending graft thrombosis. A Vr of 3.5 or more and an MGV less than 50 cm/s are the best predictive measures. Repair of correctable graft lesions with a Vr of 3.5 or more, or inflow, outflow, or graft lesions associated with an MGV less than 50 cm/s are recommended. Grafts without detectable inflow, outflow, or graft stenoses, regardless of MGV, may be safely followed.

BACKGROUND We undertook a population-based study of hemodialysis (HD) patients to determine which factors are important in predicting the type of permanent access initially placed and if a functional permanent access is in place at the start of HD. METHODS Selected characteristics were abstracted from the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Study (DMMS) Wave 2. Logistic regression was used to estimate the independent contribution of specific characteristics in predicting whether the initial permanent access placed was an arteriovenous (AV) fistula compared with a polytetrafluoroethylene (PTFE) graft, and in predicting whether permanent access (fistula or graft) was in place at the initiation of dialysis. RESULTS Sixty-seven percent of the patients had an AV graft placed as their first permanent access. Characteristics important in predicting if a fistula was initially placed included age (per decade; aOR = 0.84, P < 0.001), female gender (aOR = 0.52, P < 0.001), body mass index (per standard deviation; aOR = 0.70, P = 0.09), avoiding blood draws (aOR = 1.96, P < 0.001), ability to ambulate (aOR = 2.24, P = 0.008), underlying renal disease (glomerular compared with diabetes, aOR = 2.19, P = 0.009), college education (aOR = 1.72, P = 0.002), and sharing in decision making (aOR = 1.50, P = 0.02). Thirty-four percent of patients (34.4%) had functional permanent access at the start of HD. Characteristics important in predicting which patients had functional permanent access included serum albumin (per 1 mg/dL increase, aOR =1.55, P = 0.003), erythropoietin prior to starting HD (aOR = 1.79, P = 0.002), fewer predialysis nephrologist visits (aOR = 0.21, P < 0.001), and when the patient was told they had renal disease (aOR = 0.33, P = 0.002). CONCLUSIONS PTFE grafts were the most common initial permanent access. The majority of patients did not have permanent access at the start of dialysis. Factors that are thought to compromise identification of adequate veins were important predictors of PTFE graft placement. Permanent access at the start of HD was largely a function of early patient education and early referral to a nephrologist.

Split-thickness skin grafts are commonly used for the treatment of acute eyelid burns; in fact, this is dogma for the upper lid. Ectropion, corneal exposure, and repeated grafting are common sequelae, almost the rule. It was hypothesized that for acute eyelid burns, the use of full-thickness skin grafts, which contract less than split-thickness skin grafts, would result in a lower incidence of ectropion with less corneal exposure and fewer recurrences. The records of all patients (n = 18) who underwent primary skin grafting of acutely burned eyelids (n = 50) between 1985 and 1995 were analyzed retrospectively. There were 10 patients who received full-thickness skin grafts (12 upper lids, 8 lower lids) and 8 patients who received split-thickness skin grafts (15 upper lids, 15 lower lids). Three of 10 patients (30 percent) who received full-thickness skin grafts and 7 of 8 patients (88 percent) who received split-thickness skin grafts developed ectropion and required reconstruction of the lids (p = 0.02). No articles were found substantiating the concept that only split-thickness grafts be used for acute eyelid burns. The treatment of acute eyelid burns with full-thickness rather than split-thickness skin grafts results in less ectropion and fewer reconstructive procedures. It should no longer be considered taboo and should be carried out whenever possible and appropriate.

The relationship between atherosclerotic renal artery stenosis (ARAS) and blood pressure control remains poorly understood. Duplex ultrasonography is a noninvasive method for detecting and grading ARAS. The purpose of this study was to characterize the relationship between the degree of ARAS, levels of blood pressure, and control of blood pressure with antihypertensive medication. A cross-sectional analysis was performed on 139 patients with ARAS. All patients had at least one diseased renal artery by duplex ultrasound. Renal arteries were classified as normal, less than 60% stenosis, or 60% or greater (high-grade) stenosis. Data regarding blood pressure, coexisting risk factors, and medications were collected. The extent of ARAS was significantly associated with progressive elevation of the systolic blood pressure, whereas the diastolic component was elevated in the case of unilateral high-grade stenosis: no high-grade stenoses, 153 +/- 22/81 +/- 10 mm Hg; unilateral high-grade stenosis, 162 +/- 22/86 +/- 9 mm Hg; and bilateral high-grade stenoses, 174 +/- 27/82 +/- 9 mm Hg (P = 0.002 systolic; P = 0.02 diastolic). Eighty-two percent of the patients were taking known antihypertensive medications. Angiotensin-converting enzyme inhibitor (ACEI) usage versus nonusage was associated with a significantly lower systolic (157 +/- 27 v169 +/- 22 mm Hg; P = 0.03) and diastolic (79 +/- 9 v 85 +/- 9 mm Hg; P = 0.001) blood pressure. The effect of ACEI usage was observed in patients with high-grade ARAS. None of the other classes of antihypertensive medications were associated with significantly lower blood pressure. In patients with ARAS, blood pressure levels were correlated with the severity of renal artery disease. Patients taking ACEIs had significantly lower blood pressures, and the effect of ACEI usage was strongest among patients with unilateral ARAS.