Originally thought to be a disadvantaged outflow source, the dorsalis pedis artery is associated with excellent patency and limb salvage in the diabetic population. The aim of this study was to demonstrate that the dorsalis pedis artery is as durable in nonbiabetics as in their diabetic counterparts. During a 21-year period from 1979 to 1999, 299 long lower limb bypasses to the dorsalis pedis artery were performed at our institution. Patient data and outcomes were reviewed from the vascular registry. Statistical analysis and patency rates were compared using chi-squared and log-rank analysis. This study confirms that the dorsalis pedis can be used as an outflow source with durability that is comparable in both diabetics and nondiabetics. No significant difference exists in morbidity, mortality and patency rates. In the nondiabetic, when the dorsalis pedis is the only patent distal vessel, amputation can be avoided if one considers this a suitable option as an outflow source.

Patients with severely diseased or occluded infrageniculate arteries, limited runoff, and tissue loss may often present for primary amputation. In this study, we review our experience with plantar artery revascularization when no other bypass options are feasible. All patients requiring infrainguinal bypass to the plantar artery level over the last 3 years were prospectively entered into our vascular surgery database. Indications, demographics, length of stay (LOS), outcome, and patency were reviewed. Our results showed that plantar artery bypass is a safe and reasonable alternative to primary amputation. Excellent limb salvage can be achieved if the bypass remains patent through the initial 30 days postoperatively.

Vascular care, diagnosis, and intervention can be very complex. Multiple specialists commonly are involved in dealing with patients with systemic atherosclerotic disease. Although each specialist may provide state-of-the-art care with good result, it would be advantageous to minimize duplication of effort and thereby improve cost efficiency. Patients still could reap the benefit of all these disciplines if evaluated for their vascular complaint in a coordinated system. In doing so, atherosclerosis prevention with risk factor modification, as well as diagnosis and therapy for the presenting problem all can be simultaneously managed. This is the concept that has motivated groups such as our own to form a comprehensive vascular center. We describe our experience with establishing a vascular center and outline its benefits and limitations.

Carotid endarterectomy by the eversion technique allows for all of the benefits of conventional endarterectomy but obviates the need for a distal suture line on the smaller internal carotid artery, and thus batching. Carotid artery reanastomosis onto the bifurcation can be quickly and simply performed with almost no risk of closure-related restenosis, given the anastomosis is on the larger of 2 arteries. In our experience of over 3,000 eversion carotid artery endarterectomies, the restenosis rate has been less than 1% judged by rigorous duplex follow-up. In this article, the technique and utility of eversion carotid endarterectomy is discussed.

The goal of clinical pathways is to reduce the cost of the hospitalization while maintaining acceptable results (patency, morbidity, and mortality). Patients who present with lower extremity revascularization pose a difficult problem, for they have significant comorbid medical disease. In this study the authors analyze their results and the treatment cost for patients undergoing lower extremity revascularization before and after the institution of clinical pathways. Data were collected independently by the hospital financial office, and surgical outcomes were derived from the prospectively collected computerized vascular registry. Data were analyzed for 12 months before and after institution of pathways. Cost, length of stay (LOS), and use of ancillary service as well as mortality, morbidity, and patency rates were evaluated. During each period, patients were selectively admitted to the intensive care unit based on perioperative risk factors independent of the pathway. Three hundred ninety-nine patients with distal reconstructions were placed on the path during this time period. These were compared to a group of 286 patients who were not on the path in the year prior. The LOS decreased from 14.3 days to 9.2 days. Electrolyte laboratory panels decreased from 12 draws per patient per admission to two draws per patient per admission. This trend was also seen in complete blood count (11.8 to 6.8), glucose (12.6 to 2.1), and electrolytes (12.2 to 1.8). Perioperative mortality rates were similar (2.5% vs 1.9%) with no change in morbidity rates. Total cost for hospitalization decreased by 27% after institution of the clinical pathway. From these data, the authors can demonstrate that the institution of clinical pathways not only decreased total cost, use of ancillary laboratory tests, and LOS but also did not negatively impact on outcome.

With the graying of America comes an increasing demand for medical care of the elderly. Unfortunately, due to a combination of rising costs of health care and driving force from the public to lower spending, health maintenance organizations and insurance companies are less willing to pay for expensive surgical procedures. Recently, infrainguinal arterial reconstructions have been denied at our institution solely on the basis of patient's age, without adequate assessment of data. We evaluated the results of patients aged over 80 years who underwent infrainguinal reconstruction and compared them to results of younger cohorts during the same time period. From 1989 to 1998, 629 octogenarians had infrainguinal reconstructions performed at our institution. In the same time period, 3257 procedures were performed on patients <80 years old. Demographics, indications for operations, and outcomes were compared. Statistical analysis was performed with Fisher's exact test and log rank analysis, assuming significance for p < 0.05. Indications for operation were significantly more often limb salvage and less often claudication in the older group. Nonfatal complication rates were similar. Primary and secondary patency rates as well as limb salvage rates were comparable in both groups. Patients who are >80 years of age should expect comparable outcomes to those of their younger cohorts when undergoing infrainguinal reconstructions. Health care dollars can be well spent on octogenarians and age should not be a contraindication for infrainguinal reconstruction.

Objective To evaluate the short- and long-term results of surgical reconstruction of the renal arteries, the authors review their experience with more than 600 reconstructions performed over a 12-year period. Summary Background Data Reconstruction of the renal arteries, whether for primary renal indications or concomitantly with aortic reconstruction, has evolved over the past 40 years. There is concern that renal artery reconstructions carry significant rates of mortality and morbidity and may fare poorly compared with less-invasive procedures. Methods From 1986 to 1998, 687 renal artery reconstructions were performed in 568 patients. Of these, 105 patients had simultaneous bilateral renal artery reconstructions. Fifty-six percent of the patients were male; 11% had diabetes; 35% admitted to smoking at the time of surgery. Mean age was 67 (range, 1 to 92). One hundred fifty-six (23%) were primary procedures and the remainder were adjunctive procedures with aortic reconstructions; 406 were abdominal aortic aneurysms and 125 were aortoiliac occlusive disease. Five hundred procedures were bypasses, 108 were endarterectomies, 72 were reimplantation, and 7 were patch angioplasties. There were 31 surgical deaths (elective and emergent) in the entire group for a mortality rate of 5.5%. Predictors of increased risk of death were patients with aortoiliac occlusive disease and patients undergoing bilateral simultaneous renal artery revascularization. Cause of death was primarily cardiac. Other nonfatal complications included bleeding (nine patients) and wound infection (three patients). There were 9 immediate occlusions (1.3%) and 10 late occlusions (1.5%). Thirty-three patients (4.8%) had temporary worsening of their renal function after surgery. Conclusion Renal artery revascularization is a safe and durable procedure. It can be performed in selected patients for primary renovascular pathology. It can also be an adjunct to aortic reconstruction with acceptable mortality and morbidity rates.

Renal artery aneurysms are being encountered with increasing frequency owing to the more liberal use of sensitive diagnostic imaging. Despite numerous historical reports, some controversy exists regarding the clinical significance of small (<2.5 cm) renal artery aneurysms. At their institution the authors favor an aggressive approach in the management of extraparenchymal renal artery aneurysms. This study comprises their experience over the last 7 years. From 1989 to the present, 22 renal artery aneurysms were discovered at their institution. All patients were offered surgical repair, and three of the 22 refused surgery. Two of the patients who refused had asymptomatic aneurysms < 2 cm in size, and the other eventually expired from aortic dissection. The surgically treated patient population consisted of seven men and 12 women with a mean age of 56.9 years (range 11-79). Seven patients were asymptomatic, two presented with pain, eight were hypertensive, five had an associated abdominal aortic aneurysm, one had occlusive disease, and one patient had neurofibromatosis. The aneurysms had a mean size of 2.4 cm (range 1.5-4.0) and occurred at the main renal artery (seven patients), or at the hilar bifurcation (11 patients), or at a secondary bifurcation (one patient). All surgical repairs were performed via a retroperitoneal approach. Procedures included 11 arterioplasties, four polytetrafluoroethylene (PTFE) bypasses based on aortic replacement grafts, one renal artery reimplanted into the aortic replacement graft, two aortic based Goretex bypasses, and one interposition vein bypass. Operative mortality for these patients was 0%. No patient had worsening of renal function based on values preoperative and postoperative blood urea nitrogen/creatinine values. Four patients with preoperative hypertension and with saccular-type bifurcation aneurysms who underwent arterioplasty are now normotensive and require no antihypertensive medication. Mean follow-up for these patients is 1.5 years and duplex ultrasound revealed all reconstructed arteries or bypasses to be patent. These data suggest that extraparenchymal renal artery aneurysms can be safely repaired operatively with minimal morbidity and mortality rates.

Although the quality of the distal run-off has been considered as an important factor affecting the success of bypass grafting, reasonable results have nevertheless been reported for bypass grafts to a popliteal artery with no direct communication with the tibial or peroneal vessels (isolated popliteal segment, IPS). The use of autogenous vein has produced the best results in this situation with most authors finding polytetrafluoroethylene (PTFE) less satisfactory. Improved results have nevertheless been shown for femoro-popliteal and femorotibial PTFE grafts by the incorporation of vein patches into the anastomoses. In this paper, the influence of this technique on the patency of PTFE grafts to IPS is evaluated. Thirty-three PTFE grafts to an IPS and 67 to the below knee (BK) popliteal artery with one or more run-off vessels were studied. All IPS grafts were carried out for limb salvage and in the BK popliteal group, 46 (69%) were for limb salvage and 21 (31%) were for severe claudication. Groups were matched in terms of age, smoking history and prevalence of diabetes mellitus. Cumulative patency rates of 84% at 1 year and 76% at 3 years were achieved in the IPS group compared to 90 and 81% for the BK popliteal group with one or more run-off vessels. Using the Taylor patch technique, comparable 3 year patency rates can be expected for PTFE grafts to IPSs and to BK popliteal arteries with patent tibial or peroneal run-off.

Adaptation of new clinical products should be based upon thorough scientific evaluation of properties and performance in vitro and in vivo. Developmental animal research experimentation is classically carried out by the manufacturer with eventual government approval. However, objective data needs to be recorded during clinical trials including handling characteristics, bleeding, tensile strength, kinking, seamline break, dilatation, anastomotic deterioration, patency, and incorporation. Since April 1991, 1010 stretch polytetrafluoroethylene (PTFE) aortic grafts have been implanted at our institution and data were recorded prospectively. Six hundred and seven were for elective abdominal aortic aneurysms, 46 for symptomatic abdominal aortic aneurysms, 58 for ruptured abdominal aortic aneurysms, 17 for elective thoracoabdominal aneurysms, 3 for ruptured thoracoabdominal aneurysms and the remainder were for various aortoiliac pathology. Average age of the patients was 69 (range: 10-95), 66% were males, 25% were diabetics. Overall operative mortality was 5.8% (2.9% in elective cases and 26.6% in emergent cases). There were 23 occlusions; 21 were revised and 2 were replaced with axillofemoral bypasses. Estimated blood loss was 784 cc in elective cases and 1918 cc in emergent cases. Grafts were followed by duplex ultrasound or CT scan every 3 months during the first year and every 6 months thereafter. There were no graft dilatations or false aneurysms in this series. There was one graft infection and no perigraft seromas or anastomotic deteriorations during this follow up. Follow up was complete in 94% of these patients. In conclusion, stretch PTFE graft has acceptable handling characteristics, no excessive bleeding at the suture line and had no anastomotic or graft dilatation. This graft material was suitable for thoracic, visceral, renal and abdominal aortic reconstructions.

To discuss the most important risk factors in patients who undergo surgical repair of an abdominal aortic aneurysm (AAA).This update in vascular surgical repair highlights the criteria that identify high-risk patients, the useful preoperative tests, and the perioperative measures that can aid surgical recovery.In elective repair of AAAs, high-risk patients are those with severe coronary or valvular heart disease, decompensated chronic obstructive pulmonary disease, severe cerebrovascular disease, chronic renal failure, hepatic cirrhosis with portal hypertension, and chronic hematologic disorders associated with bleeding dysfunction. Patients with unstable or severely symptomatic heart disease should undergo preoperative coronary angiography and ventriculography. Pharmacologic stress testing is recommended for patients with clinical markers of serious coronary artery disease and other medical or physical factors that prevent any type of standard exercise stress testing.Our experience with high-risk patients supports conventional repair of AAAs. Our preference for the midline abdominal incision in high-risk patients is substantiated by an operative mortality rate of 5.7% in comparison with a reported 7% mortality rate for nonresective therapy. Approximately one in three high-risk patients will have a serious postoperative complication, the most common of which is a cardiac event. Most patients recover after a slightly prolonged hospital stay.Despite an increased operative risk, patients with a stable medical condition and an AAA larger than 6 cm in diameter should be considered for elective repair. High-risk patients with smaller aneurysms (5 to 6 cm in diameter) should undergo efforts to stabilize or to improve their general medical condition before elective operation.

New unconventional oil extraction technologies are needed because conventional technologies to extract gas and oil from oil shale or tar sands are both economically unfeasible and ecologically devastating. One technology proposed in this paper is built on long-standing proposals to explode a nuclear bomb in the heart of an oil shale deposit which in a flash causes the release of gas and oil from the oil shale. This rubble chimney will have a glassy bottom which seals the oil from sinking into the earth, thus preventing damage to the aquifer. The authors show that the equivalent of a significant atomic bomb can be achieved using conventional explosives or liquid oxygen and carbon. The computations further show that the amount of carbonous material lost in the explosion is a small price to pay for the safe in situ collection of the oil and gas. Computations show that this technology is both physically possible and economically feasible. A second approach is using the supercritical state — that exact point between liquid and gas — to extract the oil and gas from the oil shale and from the tar sands. In one configuration, the supercritical state is achieved by a sea-based configuration using the weight of water to provide sufficient pressure. A land-based alternative is a pressure well — a very deep well that similarly achieves sufficient pressure to produce the supercritical state. Supercritical carbon dioxide is frequently used in extraction using the supercritical state and the specific technology using carbon dioxide both in devices as well as in high pressure in situ. To contain the pollutants and maximize the output, a plasma tunneler heats the oil shale in situ and collects the oil and gas while the gases are contained in inflatable domes at the “worm hole” or the aperture that the earth penetration device was fed from. Other non-combustion proposals are advanced as well.

Purpose: This study was undertaken to examine the role of superficial and deep venous reflux, as defined by duplex-derived valve closure times (VCTs), in the pathogenesis of chronic venous insufficiency.Methods: Between January 1992 and November 1995, 320 patients and 500 legs were evaluated with clinical examinations and duplex scans for potential venous reflux. VCTs were obtained with the cuff deflation technique with the patient in the upright position. Imaging was performed at the saphenofemoral junction, the middle segment of the greater saphenous vein, the lesser saphenous vein, the superficial femoral vein, the profunda femoris vein, and the popliteal vein. Not all patients had all segments examined because tests early in the series did not examine the profunda femoris or lesser saphenous vein and because some patients had previous ligation and stripping or venous thrombosis. VCTs were examined for individual segment reflux, grouped into superficial and deep systems, and then correlated with the clinical stage as defined by the SVS/ISCVS original reporting standards in venous disease. Segment reflux was considered present if the VCT was greater than 0.5 seconds, and system reflux was considered present if the sum of the segments was greater than 1.5 seconds. Between-group differences were analyzed with analysis of variance and post hoc tests where appropriate.Results: Sixty-nine limbs studied were in class 0, 149 limbs were in class 1, 168 limbs were in class 2, and 114 limbs were in class 3. VCTs in the superficial veins were significantly lower in class 0 than in the other clinical classes. There was no difference in superficial reflux in the symptomatic limbs (classes 1 to 3). Reflux VCTs in the superficial femoral and popliteal veins increased as the clinical symptoms progressed, with a significant increase in class 3 ulcerated limbs when compared with nonulcerated limbs. The incidence of deep venous reflux was 60% in class 3 limbs, compared with 29% in class 2 limbs, whereas the incidence of superficial venous reflux did not differ among the symptomatic limbs. Isolated superficial femoral and popliteal vein reflux was uncommon, even in class 3 limbs, but combined superficial femoral and popliteal vein reflux was found in 53% of class 3 limbs, compared with 18.5% of class 2 limbs.Conclusions: Reflux in the deep venous system plays a significant role in the progression of chronic venous insufficiency. Deep system reflux increases as clinical changes become more severe, with significant axial reflux contributing to ulcer formation. (J Vasc Surg 1996;24:755-62.)

Management of infected ischemic diabetic limbs requires antibiotic therapy, abscess drainage, and revascularization. However, revascularization is often delayed for several days or weeks as the infection is controlled. In an effort to decrease hospital stay and costs and to increase limb salvage, a series of 974 extremities with distal occlusive disease were managed with autogenous distal bypass. Some 136 of these limbs (125 diabetic) had severe invasive infections. These patients received intravenous antibiotics in all cases and abscess drainage if necessary. Vascular reconstruction was carried out as soon as possible, within 48 h of admission. An in situ bypass was used preferentially (107 cases). Patients were maintained on intravenous antibiotics in the perioperative period. Partial foot amputations, when necessary, were performed in 111 cases, usually 3–5 days after vascular reconstruction. There were no graft infections or major wound infections. There were two cases of skin edge necrosis requiring reoperation due to flap mobilization and consequent ischemia. Urgent revascularization with an autogenous conduit may be carried out in patients with invasive foot infections expeditiously, with high rates of limb salvage. Graft and wound infections are not common in this setting. Costly prolonged pre-bypass hospitalization in these cases is unnecessary. Copyright © 1996 The International Society for Cardiovascular Surgery.

In order to identify major risks for death and complications from elective repair of abdominal aortic aneurysm, the authors analyzed their experience with the last 1000 such repairs over a 15-year period. Of the patients, 772 were men and 228 were women; average age was 70 (range 37–92) years. Some 20% of the patients had severe chronic obstructive pulmonary disease and 33% had baseline creatinine level > 115 μmol/l. Fifteen patients were dialysis-dependent and 24% (2421000) had significant cardiac disease. Operation used a retroperitoneal approach in 834 patients and a transperitoneal approach in 166. The perioperative mortality rate was 2.4%, but this did not change either chronologically or with technique: some 50% of the deaths were due to cardiac causes. Renal and pulmonary impairment did not affect mortality or complication; 64% of non-fatal complications were distributed in the renal (17%), pulmonary (19%) and cardiac groups (28%). The authors' experience showed that patients with cardiac disease remain at significant risk for post-abdominal aortic aneurysm repair complications in spite of selective preoperative cardiac evaluation. Renal and pulmonary risk factors did not cause additional mortality or morbidity. They suggest that elective abdominal aortic aneurysm repair can be performed with low mortality and morbidity, even in increasing numbers of high-risk patients. Copyright © 1996 The International Society for Cardiovascular Surgery.

One of the perceived limitations of the left retroperitoneal approach to the aorta is inadequate access to the right renal artery. Many consider the need for a concomitant right renal artery revascularization a contraindication to performing an aortic reconstruction through the left retroperitoneum. Exposure of the right renal artery can be difficult due to the posterior course of the artery behind the vena cava. However, when the aorta is transected, the right renal artery can be easily approached with anterior and cephalad displacement of the aortic root. Over the past 3 years, 52 patients have had right or bilateral renal artery revascularization via the left retroperitoneal approach; of these procedures, 37 were performed with concomitant aortic procedures. In total, 34 patients had bilateral and 18 had unilateral revascularizations. Five patients had a transaortic endarterectomy performed, and 36 were bypassed with 6-mm expanded polytetrafluoroethylene side limbs from the aortic graft. Indications for revascularization were: 39 for suprarenal aortic bypass, seven for renal salvage and six for primary renovascular hypertension. All reconstructions have remained patent and all have been followed by serial duplex and renal flow scans (follow-up for 1-42 months). The operative mortality rate was 5.8% (3/52). There were no major cardiorespiratory complications in this group. Adequate exposure to the proximal right renal artery can be obtained through the left retroperitoneal approach to the aorta, and successful revascularization of one of both renal arteries can be technically performed with acceptable mortality and morbidity.