John W. York

Surgical implications of early failed endovascular intervention of the superficial femoral artery

BACKGROUND It is generally accepted that failed infrainguinal bypass with prosthetic material significantly compromises arterial run off, which may limit future revascularization. It is well known that the negative consequences of early vein graft thrombosis are limited, but the effect of failed peripheral angioplasty on the distal vasculature is poorly studied. The purpose of this study was to determine whether early failure after superficial femoral artery intervention influences subsequent revascularization options. METHODS Between July 1, 1998, and June 30, 2006, 276 patients underwent endovascular intervention of the superficial femoral artery. A prospective analysis of angiograms done before the intervention and after early failure (<or=200 days) was performed in a blinded fashion by three attending vascular surgeons to determine the optimal distal bypass site if an operation were to be performed. Inter-rater reliability of the angiogram scores was assessed using the Fleiss generalized kappa for multiple raters. Potential distal anastomotic sites were classified as above knee popliteal, below knee popliteal, tibial, or no adequate site. A consensus classification was determined for each patient (2 of 3 raters). RESULTS Of the 276 patients who underwent endovascular intervention of the superficial femoral artery, early failure was noted in 24 limbs in 23 patients. Angiographic records were available for 21 limbs in 20 patients (60% men; mean age, 65.3 +/- 11.3 years), of which 60% had critical limb ischemia, 40% had claudication, and 65% had diabetes. The distal bypass site was altered in six limbs (28.6%); four from popliteal to tibial and two from above knee to below knee popliteal. Inter-rater reliability was 0.54 (moderate/good). The procedures performed on these early failures were percutaneous transluminal angioplasty +/- stent (n = 14), infrainguinal bypass (n = 5), and no treatment (n = 1). Only 0.4% (1 of 276) of patients required major limb amputation due to early failure of a superficial femoral artery intervention. CONCLUSIONS Early failure after isolated endovascular intervention of the superficial femoral artery is infrequent and alters the distal target in 30% of early-failure patients if open bypass is planned. Salvage with repeat angioplasty, if necessary, can be accomplished in most patients, and the need for limb amputation is exceedingly rare. The early failure results in this study support a more liberal application of endovascular intervention to the superficial femoral artery in patients with lower extremity ischemia, especially claudication. The repercussions of late endovascular failure as well as the effects of disease progression need further study.

Comparison of open transabdominal AAA repair with endovascular AAA repair in reduction of postoperative stress response

Operative intervention causes a necessary biologic response known as the hypermetabolic stress response. Less invasive operative procedures may cause fewer metabolic and endocrine derangements. To evaluate the metabolic and endocrine differences between endovascular and transperitoneal abdominal aortic aneurysm (AAA) repair, 10 patients underwent standard open repair (open group) and 10 patients underwent endovascular repair of AAA (endovascular group) with a modular bifurcated endograft. Blood samples were obtained prior to general anesthesia (baseline) and every 6 hr for a 24-hr period. Assays for hormones related to the postoperative stress response as well as retinol-binding protein were performed. Peak hormonal values are presented in relation to the baseline. Demographic analysis of the two groups showed that there were no significant differences in age or ASA classification. The open group had a 9.6-fold increase in epinephrine release, which was significantly higher than the 1.6-fold increase in the endovascular group (P < 0.05). Elevations in cortisol were also significantly higher in the open group. Early postoperative nutritional derangements, as reflected by the levels of retinol-binding protein, were far less in the endovascular group than in the open group. Endovascular AAA repair appears to be associated with a marked reduction in the hypermetabolic stress response and nutritional deterioration, compared to traditional open repair. This reduction in physiologic stress may have salutary effects on the incidence of postoperative medical morbidity.

Development of oral heparin therapy for prophylaxis and treatment of deep venous thrombosis.

OBJECTIVE To review the current research and published literature regarding the development of oral heparin therapy for the prophylaxis and treatment of deep venous thrombosis. BACKGROUND Currently, the accepted practice of prophylaxis and/or treatment of acute deep venous thrombosis (DVT) is intravenous or subcutaneous (SQ) heparin followed by oral warfarin or SC low molecular weight heparin (LMWH) therapy followed by warfarin. Both of which are less than ideal. More recently, advances have been made towards an effective oral heparin preparation that would resolve many of the drawbacks to the current therapies. METHODS A review of the current and relevant English literature identified via a search of the Medline database from January 1990 to present. RESULTS Initial oral heparin therapy for DVT was unsuccessful due to presumed inadequate intestinal absorption as a result of heparins molecular and structural characteristics. The development of oral heparin therapy, based on combining heparin with the carrier molecule Sodium N-(8[2-hydroxybenzoyl]amino) caprylate (SNAC) to enhance its intestinal absorption and bioavailability for the prophylaxis and treatment of DVT has been demonstrated to be effective in animal models. More recent efforts have been aimed at human trials. CONCLUSION Recent advances in prophylaxis and treatment of DVT have stimulated great interest among researchers to develop an effective, convenient, and well tolerated oral therapy. An effective oral heparin therapy may represent an ideal method of prophylaxis and treatment of DVT.

Do Current Outcomes Justify More Liberal Use of Revascularization for Vasculogenic Claudication? A Single Center Experience of 1,000 Consecutively Treated Limbs

BACKGROUND The purpose of this study was to reconsider current recommended treatment guidelines for vasculogenic claudication by examining the contemporary results of surgical intervention. STUDY DESIGN We performed a retrospective review of 1,000 consecutive limbs in 669 patients treated for medically refractory vasculogenic claudication and prospectively followed. Outcomes measured included procedural complication rates, reconstruction patency, limb salvage, maintenance of ambulatory status, maintenance of independent living status, survival, symptom resolution, and symptom recurrence. RESULTS Of the 1,000 limbs treated, endovascular therapy was used in 64.3% and open surgery in 35.7% of patients; aortoiliac occlusive disease was treated in 70.1% and infrainguinal disease in 29.9% of patients. The overall 30-day periprocedural complication rate was 7.5%, with no notable difference in complication rates when comparing types of treatment or levels of disease. Overall reconstruction primary patency rates were 87.7% and 70.8%; secondary patencies were 97.8% and 93.9%; limb salvage, 100% and 98.8%; and survivals, 95.4% and 76.9%, at 1 and 5 years, respectively. More than 96% of patients maintained independence and ambulatory ability at 5 years. Overall symptom resolution occurred in 78.8%, and symptom recurrence occurred in 18.1% of limbs treated, with slightly higher resolution and recurrence noted in patients treated with endovascular therapy. CONCLUSIONS Contemporary treatment of vasculogenic claudication is safe, effective, and predominantly endovascular. These data support a more liberal use of revascularization for patients with claudication and suggest that current nonoperative treatment guidelines may be based more on surgical dogma than on achievable outcomes.

Thoracoabdominal Aortic Aneurysm Repair

1. Double-lumen endotracheal intubation. 2. Spinal drainage. 3. Right lateral decubitus thoracoabdominal positioning. 4. Thoracoabdominal incision terminating over appropriate interspace (type IV: eighth to ninth interspace; types I, II, and III: fifth interspace). 5. Large aneurysms may require two intercostal incisions. 6. Peritoneum left intact with retroperitoneal exposure. 7. Intra-abdominal contents reflected to the right.

Contemporary Management of Diabetic Neuropathic Foot Ulceration: A Study of 917 Consecutively Treated Limbs

BACKGROUND For patients with diabetic neuropathic foot ulceration, the current treatment paradigm is heavily weighted toward limb revascularization; aligning incentives to perform more surgery and less ulcer management/prevention. Our purpose was to perform an analysis of functional outcomes to assess this current treatment paradigm. STUDY DESIGN Nine hundred and seventeen neuropathic ulcerated feet in 706 patients with diabetes were analyzed. Four hundred and sixty limbs (50.2%) had concomitant ischemia, 219 of which were revascularized (137 angioplasty and 82 open surgery). Outcomes measured included ulcer healing, survival, limb salvage, amputation-free survival, maintenance of ambulation, and independence. Independent predictors of outcomes were measured using an Extended Cox Model. RESULTS Overall outcomes (n = 917) were: ulcer healed, n = 250 (27%; mean time to healing 33 weeks); functionally healed, n = 488 (53%; mean time to functional healing 29 weeks); 5-year limb salvage, 68%; survival, 38%; amputation-free survival, 30%; maintenance of ambulation, 64%; and maintenance of independence, 74%. There was little difference in ulcer healing rates for patients with or without ischemia (28.5% versus 26%; p = 0.4). However, ischemia was a significant marker of poor outcomes (nonischemic ulcer, ischemic ulcer revascularized, and ischemic ulcer not revascularized: 5-year limb salvage of 80%, 61%, and 51%; p < 0.001); survival (47%, 37%, and 24%; p = 0.03); amputation-free survival (37%, 28%, and 17%; p < 0.001); maintenance of ambulation (74%, 55%, and 55%; p < 0.001); and maintenance of independence (82%, 72%, and 58%; p = 0.01). Wound healing was an independent predictor of survival and amputation-free survival (survival: hazard ratio = 0.58; 95% CI,0.46-0.73; amputation-free survival: hazard ratio = 0.42; 95% CI, 0.33-0.53). CONCLUSIONS The current treatment paradigm is associated with relatively poor healing rates and substantial late morbidity and mortality. Although revascularization is effective treatment for ischemia, it is probably overvalued when compared with the potential improvement afforded by better medical foot wound management.

Transabdominal Replacement of Abdominal Aortic Aneurysms

Aneurysmal disease of the abdominal aorta was responsible for approximately 16,000 (0.7%) deaths in the United States in 1999. It was the 11th leading cause of death during the same time period for the age range of 65–79 years (National Vital Statistics Reports 2001). The overall incidence is increasing and this is unrelated to the general aging of the population (Cronenwett et al. 2000; Hollier et al. 1992). Males have a four to six times higher prevalence than females and Caucasians are affected more often than other races. Population-based studies vary but generally agree that the overall prevalence in patients >55 years of age is roughly 6.0% in males and 1.5% in females (Pleumeekers et al. 1995; Singh et al. 2001). Differences in the criteria used to define aneurysms may account for the disparity of various reports. Currently, accepted standards classify an abdominal aorta as aneurysmal if an isolated segment of the infrarenal aorta is ≥3.0 cm in diameter or if the diameter of the infrarenal aorta is 1.5× the diameter of the suprarenal aorta (Cronenwett et al. 2000). Aneurysm size is the most important prognostic factor in determining the risk of aneurysm rupture.