Search

Objective: We previously developed the use of side to side (s-s) bypass for the treatment of adult moyamoya disease (MMD) and discovered several kinds of distinct blood flow models intraoperatively, which we observed through indocyanine green-video angiography (ICG-VA). The purpose of this paper was to investigate the correlation between blood flow model (BFM) identified in s-s bypass and the incidence of postoperative cerebral hyperperfusion syndrome (CHS) among patients with MMD. Methods: We analyzed 166 hemispheres from 153 patients diagnosed with MMD, including 118 hemispheres with s-s bypass and 48 with end to side (e-s) bypass. We categorized the enrolled patients into three pairs of comparison groups based on postoperative CHS (CHS or non-CHS) in s-s bypass, blood flow models (BFM I or BFM II) and surgical approach (s-s bypass or e-s bypass). Patients' demographics and characteristics were compared between groups. Results: Among patients who developed CHS, the occurrence of BFM I was more frequent than that of BFM II (0.154 vs. 0.019, p = 0.029 < 0.05) and no significant differences were noted in the remaining data. In the group of blood flow models, the proportion of patients with a history of cerebral hemorrhage was higher in BFM II compared to BFM I (0.062 vs. 0.226, p = 0.009 < 0.05), and the incidence of severity of ischemia was found to be higher in BFM I than in BFM II (0.774 vs. 0.429, p = 0.011 < 0.05), while the postoperative modified Rankin Scale (mRS) score and the Matsushima grade displayed no obvious difference. In comparison with the occurrence of CHS in e-s bypass group (7/48, 0.146), s-s bypass group had no difference (11/118, 0.093; p = 0.323 > 0.05), BFM I group showed no discrepancy (10/65, 0.154, p = 0.906 > 0.05) while BFM II group was different (1/53, 0.019, p = 0.047 < 0.05). Conclusion: The proportion of postoperative CHS occurring in BFM II during s-s bypass was lower than that in e-s bypass and BFM I. The postbypass blood flow model in s-s bypass may serve as a novel predictor for postoperative CHS. [ABSTRACT FROM AUTHOR]

Parodi first introduced endovascular aneurysm repair (EVAR) in 1991 and since that time it has been shown to have a lower 30-day morbididty and mortality compared to open surgery. Anatomic constraints governed by the need for adequate access vessels, and sufficient proximal and distal landing zones, as well as the need for long-term surveillance, have been the main limitations of this technology. Anatomic factors were initially estimated to exclude 40% of patients with abdominal aortic aneurysm (AAA). The rapid extension of EVAR technology has been complimented by improved access to both high-quality imaging modalities and a variety of endografts. These developments have led EVAR to become a more practical alternative for patients with ruptured AAA. Early data in this setting is encouraging with even more profound reductions in morbidity and mortality than seen in the elective repair., (Copyright © 2012 Elsevier Inc. All rights reserved.)

True aneurysms of the innominate artery are rare. Successful axial reconstruction in the past has required a combined cervical and transthoracic approach with placement of a prosthetic graft. We describe herein the occurrence of an innominate artery aneurysm that extended to and involved the proximal common carotid artery and subclavian artery in a 63-year-old woman. The patient presented with thomboembolic sequelae in her fingertips and had a pulseless upper extremity. Successful aneurysmectomy and axial reconstruction with a bifurcated graft was achieved by using cervical exposure alone. A subsequent staged revascularization of the upper extremity was successfully accomplished with a brachial to radial artery bypass and ulnar artery transposition.

Background: This study evaluated the type and need for angioplasty in 253 consecutive carotid endarterectomies., Methods: Polyester knitted gelatin sealed patch (DP) and polytetrafluoroethylene (PTFE) patches were used in, respectively, 159 and 29 patients, with 65 vessels closed primarily (no patch [NP])., Results: Surgical results, estimated blood loss, and surgical time were similar in each group. Postoperative hematomas occurred in 6 DP and 3 NP patients. There were 3 strokes in the DP group. Long-term duplex evaluation was possible in 201 patients. The number of patients who had less than 15%, 15% to 50%, 50% to 79%, 80% to 99%, 100%, or an ungraded degree of narrowing were as follows for each group: DP, 117, 2, 5, 0, 1, and 2; PTFE, 18, 1, 1, 0, 0; and NP, 53, 0, 0, 0, 1. Statistical analysis failed to show any difference between groups postoperatively or in long-term follow-up evaluation., Conclusions: It appears that selective patching is safe and effective in male patients who undergo carotid endarterectomy. The type of patch material also is inconsequential. Patch type and its use should be at the surgeon's discretion.

A patient who had undergone his third orthotopic liver transplantation nearly 9 years prior to presentation developed worsening hepatic and renal function, as well as severe bilateral lower extremity edema. Magnetic resonance imaging demonstrated vena caval thrombosis from the suprahepatic venous anastomosis to the infrarenal inferior vena cava, obstructing the renal veins. This was treated by percutaneous placement of metallic stents from the renal veins to the right atrium. At 16 months clinical follow-up, the patient continues to do well.

Since the natural tendency of the aorta is to increase in diameter and tortuosity with age and since abdominal aortic aneurysms (AAAs) increase in diameter and length over time, encroaching on the renal and hypogastric orifices, early repair of AAAs (when > or =4.0 cm) may allow greater applicability of the endovascular option because of more favorable aortoiliac morphology. Patients who present at an older age with larger AAAs should be more likely to be anatomically excluded from endovascular AAA repair. Over a 42-month period, 317 consecutive patients referred with aortoiliac aneurysms (infrarenal AAA > or =4.0 cm) were evaluated by one of the authors (SGL) for endovascular vs open repair based on computed tomography (CT) and angiographic imaging. The 10 anatomic exclusion criteria were those applicable to the Zenith endograft (Cook, Inc), which currently is the most anatomically inclusive of the aortic endografts in commercial use in the United States. Based on their aortoiliac morphology, 212 patients were excluded from endovascular repair and 105 were included as acceptable anatomic candidates. Age, AAA size, and the reason(s) for exclusion were recorded for each patient. By use of Student's t test and logistic and linear regression analyses, the groups were compared by age, AAA size, and age + size. There was no significant difference in patient age or AAA size distribution between the group of patients excluded from endovascular repair based on aortoiliac morphology compared to those who met the inclusion criteria. Patients with small AAAs (4.0-5.4 cm) had similar age distribution as those with large (> or =5.5 cm) AAAs. The majority of patients (87%) were excluded based on proximal aortic neck morphology. The presence of aortoiliac morphology that precludes endovascular repair is independent of patient age or AAA size at presentation. A patient presenting with a small (4.0-5.4 cm) AAA is not more likely to be a candidate for endovascular repair than a patient with a large AAA.

Background: This study focused on 200 carotid endarterectomies (CEA) performed at our Veterans Administration Hospital (VAH) to determine whether 1-day hospitalization after CEA is safe and the degree to which it can be achieved., Methods: Over 36 months, 200 CEAs were performed for asymptomatic stenosis (n = 104), transient ischemic attacks (n = 68), and stroke (n = 28). General anesthesia was used in 189 procedures., Results: The hospital stay was 1 day for 132 procedures and more than 1 day in 68 CEAs. The average stay was 1.69 +/- 1.5 days. After surgery there were 3 strokes, 5 hematomas that required evacuation, and 5 myocardial infarctions. There were no deaths. Four patients were readmitted in the 1-day and the greater than 1-day stay groups. History of myocardial infarction, renal insufficiency, longer operative time, and complications correlated with a greater than 1-day stay (P <0.05)., Conclusion: A 1-day hospital stay is safe and practical in a VAH setting, resulting in good clinical outcomes.

In this article, a patient with extensive cerebrovascular disease who had previously undergone bilateral carotid endarterectomy and subsequent operative revision on the left side is described. The patient developed critical restenosis at the cephalic end of the previous left patch angioplasty as well as a severe stenosis of the left common carotid artery origin, which originated from a bovine aortic arch configuration. His right common and internal carotid arteries had become occluded. Endovascular treatment with two metallic stents was successfully performed through a surgical cutdown on the immediate supraclavicular portion of the left common carotid artery to establish antegrade and subsequently retrograde vascular access.

Purpose: To create a porcine hemodialysis access model that reliably reproduces intimal hyperplasia (IH) of the outflow vein similar to that which causes access failure in human patients undergoing dialysis treatments., Materials and Methods: Surgical technique for creation of side-to-side iliac-artery-to-ipsilateral-iliac-vein (IAV) native fistulas and IAV conduits was optimized in three standard-bred pigs. Persistent patency of fistulas and conduits was demonstrated in two additional pigs allowed to survive for 1 week. IAV fistulas and contralateral 2-cm polytetrafluoroethylene IAV conduits were created in five additional pigs. Venous outflow from these fistulas and conduits was evaluated with venography and intravascular ultrasound (IVUS) immediately after creation (day 0) and at 2-week intervals for as long as 64 days. Animals were killed at 30 days (n = 1), 42 days (n = 2), or 64 days (n = 2), and the arteries, veins, and conduits were evaluated histologically., Results: IAV native fistulas remained patent until the animals' death and conduits remained patent for at least 14 days in four of five pigs; both the fistula and conduit likely occluded before 16-day follow-up in the fifth pig. At 42-64 days, venography demonstrated maximum fistula outflow vein diameter stenoses of 53%-76% and maximum conduit outflow vein stenoses of 44%-84%, and IVUS demonstrated maximum area stenoses of 64%-86% and 43%-82%, respectively. Three of five conduits occluded, one before 16-day follow-up, one between 14 and 28 days, and the other after 42 days. Histologic sections demonstrated IH predominantly affecting the veins at the anastomoses and central (cephalad) to the anastomoses in all pigs., Conclusion: This porcine model reproduces IH in the fistula or conduit outflow vein with measurable stenosis. Such a model might allow relevant preclinical evaluation of interventional devices and techniques intended to reduce the effects of IH in human patients undergoing dialysis treatments.

Endovascular stent grafting of abdominal aortic aneurysms is a new technique that may replace open surgery in selected cases. Pre-and postoperative angiography can be replaced by helical CT. This pictorial essay describes and illustrates the use of multislice helical CT where maximum intensity projection and multiplanar reformats play a central role in the evaluation.

Purpose: Precise vessel sizing prior to endovascular intervention is critical to achievement of technical success. Diameter measurements obtained with CO2 and iodinated contrast material in an aortoiliac flow model were compared., Materials and Methods: Aortoiliac flow was simulated in a compliant, silicone elastomer phantom of the aortoiliac system using an autoperfusion pump (flow volume, approximately 1100 mL/min; mean arterial pressure, 70-80 mm Hg at 80-90 cycles/minute) and a glycerol solution (40% by weight; viscosity 3.7 centipoise at 20 degrees C). Digital subtraction angiography was performed with the phantom in the anteroposterior (AP) plane and in three oblique planes with both CO2 and iodinated contrast material. Five sets of images for both CO2 and iodinated contrast material were obtained for each projection. Two readers independently performed vessel diameter measurements at seven sites (distal abdominal aorta, bilateral proximal and distal common iliac, and mid-external iliac arteries). The model was then evaluated with intravascular ultrasound (IVUS) using a 20-MHz imaging catheter. Actual diameter measurements were taken from the inner wall to inner wall in orthogonal planes at the same locations within the model, as described previously. Analysis was performed to determine local difference in measurements (t tests), difference when compared to the standard AP projection with iodinated contrast material (Dunnett's test) and inter-reader variability (Pitman's test)., Results: The contralateral iliac vessel segment did not opacify when imaging with CO2 in the 45 degrees obliquities; thus, 22 of 28 sites were available for comparison. At 18 of 22 (81.8%) sites, there was significant difference in vessel measurements (P < .01), with CO2 yielding a significantly larger diameter at 17 of 22 (77.3%) of the sites. The difference in mean diameter ranged from -1.28 to 4.47 mm. With use of the AP iodinated contrast material run as the standard, there were significant differences (P < .05) in vessel diameter at 17 of 22 (77.3%) and four of 21 (19%) sites for CO2 and iodinated contrast material respectively, with CO2 tending toward greater diameter measurements. Significant differences (P < .05) in variance between the two readers were present but occurred primarily with CO2 in the AP projection and iodinated contrast material in the 45 degrees left obliquity. With use of IVUS as the standard, there were significant differences (P < .05) in the measured vessel diameters with CO2 at nine of 22 (40.9%) of the sites and with iodinated contrast material at 17 of 28 (60.7%) of the sites. Of the measurements made with CO2, seven of nine (77.8%) of the measurements were of larger diameter than those obtained with IVUS. By contrast, of the measurements made with iodinated contrast material angiography, IVUS measured larger diameters in 16 of 17 (94.1%)., Conclusion: CO2 angiography consistently yielded significantly larger vessel measurements when compared to both iodinated contrast angiography and WVUS. These results have important implications in regards to planning intervention based solely on CO2 angiography. Further evaluation is needed before recommending CO2 for vessel sizing in clinical practice.

Purpose: To evaluate the role of intercellular adhesion molecule 1 (ICAM-1) in cutaneous leukocyte trapping in venous disease, we used our rodent model of venous hypertension (VH)., Materials and Methods: VH was created in adult rats by ligation of the inferior vena cava, bilateral common iliac veins, and bilateral common femoral veins. In the Phase I experimental (exptl) group, anti-ICAM-1 monoclonal antibody (1A29) was given intravenously prior to venous ligations. Acute venous pressures were measured in the exptl and control (ctrl) (ligation only) groups. Bilateral forelimb and hindlimb skin specimens were harvested for myeloperoxidase (MPO) assay. In Phase II, VH was created in a chronic group; in a sham-operated group, ties were placed around the same vessels without ligations. Two weeks later, venous pressures were measured and radiolabeled ((125)I and (131)I) monoclonal antibody (mAb) to ICAM-1 was injected and allowed to circulate for 5 min before the level of radiolabeled antibody within forelimb and hindlimb specimens was measured., Results: In the acute study with 1A29, hindlimb pressures were significantly elevated in both the ctrl (n = 4) and exptl (n = 4) hindlimbs (15.4 +/- 0.239 and 13.8 +/- 1.89 mm Hg, respectively) compared with ctrl and exptl forelimbs (1.38 +/- 0.554 and 1.50 +/- 0.612 mm Hg, respectively). However, MPO activity was significantly elevated in the hindlimbs of the ctrl group compared with the hindlimbs of the exptl animals (19.8 +/- 1.54 U vs 6.71 +/- 2.46 U). In the chronic VH rats (n = 5) given radiolabeled anti-ICAM-1 mAb, the hindlimb pressures (10.1 +/- 4.52 mm Hg) were significantly elevated (P < 0.05) compared with forelimb pressures (1 +/- 0.447 mm Hg) and compared with the forelimb and hindlimb pressures in the sham-operated animals (n = 4) (1.63 +/- 0.813 and 4.25 +/- 2.13 mm Hg, respectively). However, there was not a significant difference in the quantity of ICAM-1-hindlimb versus forelimb or chronic VH versus sham., Conclusions: Anti-ICAM-1 mAb decreased MPO activity in hypertensive hindlimb skin, supporting the instrumental role of ICAM-1 in cutaneous leukocyte trapping. However, the constituent endothelial ICAM-1 is not elevated by VH., (Copyright 2000 Academic Press.)

Purpose: Acetazolamide (ACZ)-enhanced single photon emission computed tomography (SPECT) scans can assess both cerebral perfusion and vascular reactivity. Patients with asymptomatic critical carotid artery stenosis were evaluated for cerebral vascular reactivity to determine the effect of extracranial occlusive disease and the effect of carotid endarterectomy (CEA) on intracerebral reactivity., Methods: In 44 patients with asymptomatic critical carotid artery stenosis, cerebral perfusion and vascular reactivity were assessed before CEA with resting and ACZ-enhanced SPECT scans. All patients had a 70% or greater ipsilateral internal carotid artery stenosis. Preoperative ACZ-enhanced SPECT scans were obtained, usually 5 days before CEA. Postoperative ACZ-enhanced SPECT scans were obtained in 30 patients., Results: Preoperative SPECT scans were asymmetric, revealing focal (n = 19) or global (n = 15) decreased reactivity in 34 patients (77%). Ten patients had symmetric or normal reactivity. After CEA, 23 patients demonstrated an improvement in reactivity ipsilateral to the side of surgery. The remaining seven patients failed to improve after surgery., Conclusion: Although all patients had a high-grade internal carotid stenosis, nearly a quarter of the patients had excellent intracerebral collateral flow. Only 71% of patients demonstrated improved intracerebral vasoreactivity after CEA. The lack of improvement in the other patients may have resulted from intracerebral pathology or lack of improvement in the extracranial carotid hemodynamics.

The clinical presentation of patients with acute lower-limb ischemia and primary aortic thrombus prompted this review. Following recognition of the first case in early 1994, relevant patients (n = 6) were kept in a database and were reviewed for presentation, treatment, and follow-up. The median age was 41 and five patients were male. Angiography, computed tomography, and/or magnetic resonance angiography demonstrated one or more aortic sessile or pedunculated thrombus(i) without associated atherosclerotic disease. In two cases, a retropancreatic intraaortic mural thrombus was associated with severe pancreatitis. All other cases presented with acute lower-limb emboli requiring limb salvage embolectomy. Because of significant patient illness, systemic anticoagulation was chosen acutely to prevent recurrent emboli. Interestingly, serial studies demonstrated aortic thrombus resolution. Failure to continue warfarin therapy resulted in recurrent problems (n = 1) unless the instigating event had resolved (n = 3). There were no deaths or amputations. We concluded that surgical embolectomy, when required, with subsequent anticoagulation, results in limb salvage and allows for eventual resolution of the primary aortic thrombus. Long-term anticoagulation is required unless the etiologic process resolves. The literature describes patients with atherosclerosis and overlying thrombus but fails to describe the approach to patients with primary thrombus formation.

Background: The pathophysiologic mechanism for tissue damage in chronic venous insufficiency (CVI) is venous hypertension (VH), the primary mediator behind leukocyte trapping in tissues. We developed a new rodent model of chronic hindlimb VH to allow testing of the microvascular dysfunction that occurs in clinical CVI., Materials and Methods: Hindlimb VH was created in adult rats ( approximately 350 g, male, Wistar) by ligation of the inferior vena cava, bilateral common iliac veins, and bilateral common femoral veins. In a sham group, a loose tie was placed around the same vessels. One week later, pressure catheters were placed in the right common carotid artery, right internal jugular vein (forelimb), and right superficial epigastric vein (hindlimb). Measurements were taken 15 min later, to allow for stabilization. Bilateral forelimb and hindlimb skin specimens were harvested. The myeloperoxidase (MPO) assay, an indicator of tissue leukocyte trapping, was performed using a well-described, standard technique., Results: In the chronic rats (n = 8), the hindlimb pressures (12.6 +/- 3.2 mm Hg) were significantly elevated (P < 0.05) when compared to forelimb pressures (1.75 +/- 0.71) and to chronic sham rat (n = 6) hindlimb (3.3 +/- 1.2) pressures. There was a significant (P < 0.05) elevation of MPO activity in hindlimbs of the chronic group (32.9 +/- 13.9 units) when compared to forelimbs (17 +/- 11.3) and sham hindlimbs (18 +/- 10.2)., Conclusions: In our chronic model, as in clinical studies and previous acute investigations, we have demonstrated, using an MPO assay, an increase in the amount of cutaneous leukocytes in the hindlimbs with chronic VH but not in experimental forelimbs or sham hindlimbs or forelimbs., (Copyright 1999 Academic Press.)

Purpose: The long-term sequelae of inferior vena caval (IVC) resection during retroperitoneal lymph node dissection for metastatic nonseminomatous germ cell testis tumor (NSGCT) were assessed., Methods: Between December 1973 and September 1996, 2126 of our patients underwent RPLND for retroperitoneal nodal metastases from NSGCT; 955 had bulky disease (stages B2, B3, or C) after cytoreduction chemotherapy. Of this latter group, 65 patients (6.8%) required infrarenal IVC resection during tumor excision for cure. Our protocol does not include IVC reconstruction in such cases. Indications for IVC resection included tumor encasement or encroachment, postchemotherapy desmoplastic compression, or thrombus with tumor or clot in which cavotomy and thrombectomy cannot be performed., Results: Twenty-four of the 65 patients (postoperative follow-up period range, 11 months to 16 years; median, 89 months) were alive and able to be examined or interviewed by written and/or phone survey to assess the long-term morbidity of their IVC resection. Based on the 1994 American Venous Forum International Consensus Committee reporting standards, the clinical classifications of these 24 patients were C0A (4), C3S (4), C4A (2), C4S (13), and C6A (1). Long-term disability was mild or absent in 75% of these patients., Conclusion: Only 1 (4.2%) of the patients surveyed had chronic venous sequelae that would fulfill the accepted criteria for subsequent elective IVC reconstruction. Despite recent reports of IVC reconstruction demonstrating relatively good patency rates and low morbidity, the addition of such a complex, time-consuming procedure to extensive retroperitoneal lymph node dissection for metastatic NSGCT involving IVC resection is generally not necessary.

Purpose: Successful deployment of an endoluminal prosthesis for repair of an abdominal aortic aneurysm (AAA) is critically dependent on accurate preoperative assessment of aneurysm morphology with use of such modalities as contrast aortography (CA), spiral computed tomography (CT), magnetic resonance (MR) imaging, and intravascular ultrasonography (IVUWS). The authors describe a new phantom that could be used both to calibrate these four imaging modalities and to determine which imaging technique(s) is (are) best for preoperative AAA sizing., Materials and Methods: A life-sized AAA model was constructed of silicone elastomers with luminal access ports for introduction of contrast media and catheters. Contrast material-filled rings were positioned circumferentially along the length of the model as reference points for dimension measurements. The modalities were compared to each other relative to the actual dimensions of the model, as determined at its construction., Results: In this pilot study, all modalities were relatively similar in their ability to measure the dimensions of the AAA model. Length measurements accounted for most of the interinstitutional and interobserver variability. MR imaging had the least variability., Conclusions: The authors developed a new phantom that can be imaged successfully with CA, CT, MR imaging, and IVUS in repetitive, reproducible fashion. Structural refinements and future larger scale, statistically significant evaluations of such models should establish this as a useful adjunct in multicenter endoluminal stent-graft trials to allow calibration of imaging modalities and to determine which modality or modalities is (are) best for preoperative AAA sizing.

Purpose: We present a review of 35 patients who underwent an operation for subclavian (n = 18) or axillary (n = 17) vessel injury. In some patients, both an artery and a vein were damaged, resulting in a total of 30 arterial and 16 venous injuries., Methods: The wounding source included a gunshot (n = 19), a stab wound (n = 9,) and blunt trauma (n = 7). Seven patients had hypotension and were taken immediately to the operating room. Seventeen patients had diminished or absent pulses, whereas 13 patients had normal pulses despite an arterial injury. Associated injuries included nerve injury (n = 15), pneumohemothorax (n = 5), and fractures (n = 7). Angiography in 21 patients demonstrated an intimal flap (n = 8), extravasation (n = 5), a pseudoaneurysm (n = 3), an arteriovenous fistula (n = 2), and occlusion (n = 1). Two angiograms were normal. Arterial repair was accomplished by interposition graft (n = 17), primary repair (n = 9), patch angioplasty (n = 3,) and ligation (n = 1)., Results: No functional deficits occurred in patients with an isolated vascular injury. Seven patients with associated brachial plexus injuries experienced severe disability. One arm of a patient was amputated. Two patients died., Conclusions: The use of angiography helps to confirm and localize injuries. Prompt correction of the vascular injury avoids disability resulting from ischemia. Although the amputation rate is low with vascular repair, the functional disability resulting from associated nerve injuries can be devastating.

Background: The pathophysiologic mechanism of the skin pathology in chronic venous insufficiency is venous hypertension (VHTN). Microvascular dysfunction involving leukocytes has recently been proposed as the primary mediator of tissue damage from VHTN. We developed a rodent model allowing the investigation of the effects of acute VHTN on tissue leukocyte concentration., Materials and Methods: Under general anesthesia, adult male rats underwent transperitoneal isolation of the inferior vena cava and the common iliac veins and arteries. Bilateral thigh incisions allowed isolation of the common femoral veins and superficial epigastric veins (SEV: distal branch of the femoral vein in the thigh). Pressure in the SEV and flow in the iliac artery were measured before (T-Pre), immediately after (T-0), and for 135 min (T-1) after ligation of the cava, iliac, and femoral veins. Sham rats were identical except no venous ligation was performed. After the T-1 pressures were obtained, the distal hindlimb and forelimb skin was harvested and processed to measure myeloperoxidase (MPO) activity, an index of the number of tissue leukocytes. To evaluate the effect of arterial flow reduction known to occur with acute venous ligation, the above measurements were made in an Aortic group of rats in which the aorta was manually stenosed., Results: This venous ligation technique resulted in a significant (P < 0.05) and sustained rise in venous pressure (T-Pre, 9.91 +/- 0.94 and T-1, 26.22 +/- 2.15). Hypertensive rats had significantly elevated hindlimb MPO activity (4.77 +/- 0.36) vs forelimb (0.60 +/- 0.39), Sham (hindlimb, 0.77 +/- 0.41; forelimb, 0.10 +/- 0.05), and Aortic (hindlimb, 0.96 +/- 0.38; forelimb, 0.58 +/- 0.11) controls., Conclusions: Acute VHTN was successfully created by venous ligation in this newly developed rat model. VHTN, but not arterial flow reduction, was associated with significantly elevated hindlimb skin MPO activity, suggesting that leukocytes may indeed be mediators of skin pathology in VHTN. This model will allow further investigation into the mechanisms of microvascular dysfunction in VHTN.

Purpose: To evaluate the patency and hemodynamic impact of a cryopreserved allograft venous valve transplanted to the superficial femoral vein (SFV) of a canine insufficiency model aided by a distal arteriovenous fistula (dAVF)., Methods: Eight greyhounds had intravenous hemodynamic parameters measured (venous filling time [VFT], 90% of venous refilling time [VRT90], and simulated ambulatory venous pressure [AVP]) before (T0) and after complete hindlimb venous valvulotomy (T1) to produce venous insufficiency. Simultaneously, a valve-containing vein segment was harvested from the opposite SFV or external jugular vein (n = 1) and cryopreserved. Three weeks later a blood type-matched cryopreserved valve was transplanted to the insufficient SFV aided by a low-flow (n = 4) or high-flow (n = 4) dAVF. The fistula was ligated in 3 to 6 weeks, and venous indexes (T2) were obtained 3 weeks later. Analysis of variances compared the venous indexes at T0, T1, and T2 for statistical significance. Gross and histologic inspection assessed valve integrity., Results: Two valves aided by a low-flow dAVF exhibited thrombosis and scarring. The hemodynamics of the six remaining valves demonstrated normalization of the VRT90, an AVP consistent with insufficiency, and a VFT between normal and total venous insufficiency. The patent valves were normal on gross examination and by histologic examination with signs of normal external healing., Conclusions: A cryopreserved venous valve allograft transplanted to the SFV of an incompetent hindlimb partially corrects venous hemodynamics. A high-flow arteriovenous fistula most consistently preserves transplant patency.

Background and Methods: In 64 patients, cerebral perfusion and vascular reactivity were assessed before and after carotid endarterectomy (CEA) using acetazolamide (ACZ)-enhanced single photon emission computer tomography (SPECT). Twenty-five patients were asymptomatic, whereas the remainder were symptomatic. Sixty-one patients had a > or = 70% ipsilateral internal carotid artery stenosis., Results: Fifty SPECT scans revealed decreased vascular reactivity. Twenty-three showed infarcts. Fourteen patients had normal studies. Twenty of the SPECT scans of asymptomatic patients demonstrated poor vascular reactivity. After CEA, 39 patients had improved ipsilateral vasoreactivity. In 12 patients, contralateral improvement was also found., Conclusion: ACZ-enhanced SPECT scans, by assessing cerebral perfusion and vascular reactivity, may help to identify patients at risk of stroke should perfusion further diminish. Postoperative studies confirm improvement in vascular reactivity. ACZ-enhanced SPECT scans may provide objective evidence for the selection of patients with a high-grade asymptomatic carotid stenosis for CEA.

We report a patient who presented with acute lower extremity ischemia 13 days following removal of an intraaortic balloon pump. Dissection of the infrarenal aorta, extending into the left iliac artery, was found at operation. The patient's recent myocardial infarction, prolonged ischemia with compartment syndrome, otherwise normal aortoiliac and infrainguinal arteries and the necessity for suprarenal aortic clamping for surgical repair, were all factors in the decision for endovascular repair of the dissection. Infrarenal aortic and left iliac Wallstents, placed intraoperatively, successfully occluded the false lumen of the dissection. The patient was discharged after an uncomplicated recovery and is asymptomatic with palpable pedal pulses and triphasic pedal Doppler waveforms 1 year following the procedure.

Purpose: To determine the accuracy of two-dimensional (2D) time-of-flight (TOF) magnetic resonance (MR) angiography, performed with state-of-the-art equipment, in the evaluation of the iliac arteries., Materials and Methods: The iliac arteries of 50 patients undergoing conventional arteriography for evaluation of lower-extremity ischemia or abdominal aortic aneurysm were also imaged with axial 2D TOF MR angiography. Blinded interpretations of conventional arteriograms and MR angiograms were compared. MR angiography was performed with a 1.5-T system with 2-mm contiguous axial sections, 60 degrees flip angle, 28-msec repetition time, and 7.4-msec echo time., Results: Blinded interpretations of 2D TOF MR angiograms matched those of conventional arteriograms in 26 of 50 patients (52%). For the diagnosis of obstructive iliac artery lesions, sensitivity and specificity with MR angiography were 85% and 59%, respectively. Two of three saccular iliac artery aneurysms escaped detection with MR angiography., Conclusion: Iliac artery evaluation with axial 2D TOF MR angiography is not sufficiently accurate to warrant its use as a replacement for conventional arteriography in patients who lack contraindications to the latter.

Purpose: To develop a magnetic resonance (MR) angiography protocol, with use of breath-hold techniques, for simultaneous aortoiliac inflow assessment and renal artery screening in patients with lower extremity ischemia or aortic aneurysm., Materials and Methods: Breath-hold three dimensional gadolinium-enhanced MR angiography was performed in 50 patients (conventional arteriography in 47 was the standard of reference). After multiple strategies were tested in the first 18 patients, a final protocol was formulated and tested in the subsequent 32 patients., Results: The final protocol comprised a single-slab (28 3-mm-thick partitions) coronal acquisition (repetition time, 7 msec; echo time, 2.8 msec; flip angle, 60 degrees) during a single breath hold, enhanced with 30 mL gadoteridol. In the final 32 patients, sensitivity and specificity, respectively, for obstructive lesions were 100% and 100% for the aorta, 100% and 98% for common iliac arteries, 100% and 89% for external iliac arteries, 100% and 89% for main renal arteries, and 100% and 62% for accessory renal arteries., Conclusion: This breath-hold protocol improves the accuracy of aortoiliac inflow assessment, but low resolution limits evaluation of small renal arteries.

Renal and visceral artery images obtained concurrently with spiral CT and conventional arteriography were compared for 32 patients. Indications for imaging were occlusive disease (n = 12), aneurysmal disease (n = 9), and renal or visceral artery disease (n = 11). Conventional arteriography enabled visualization of 64 renal arteries and 15 accessory renal arteries. Lateral aortograms obtained in 15 patients enabled visualization of 14 superior mesenteric (SMA) and 14 celiac arteries. Spiral CT enabled visualization of 60 renal arteries, 12 accessory renal arteries, 27 SMAs, and 22 celiac arteries. Calcification or a disparity in timing of contrast material injection and scanning prevented visualization of the celiac artery in 10 patients and the SMA in four patients. With conventional arteriography as the standard for comparison, spiral CT had a sensitivity of 67% and a specificity of 95% for depiction of at least 75% stenosis in the main renal artery. By means of the Pearson correlation coefficient, significant correlation (p < 0.001) was confirmed between spiral CT and arteriography for evaluation of stenosis of the main renal artery, SMA, and celiac artery. This early experience suggests that spiral CT may be useful in evaluation of renal and visceral arteries and their relationship to aortic disease.

Background: Thirty-eight limbs with iliac occlusive disease were treated with Palmaz stents from 1987 through 1991., Methods: Indications for stent utilization included dissection induced by percutaneous transluminal balloon angioplasty (PTA) (10), restenosis after PTA (nine), post-PTA residual stenosis (nine), multiple stenoses or occlusion (five), and unfavorable location (five)., Results: The ankle/brachial pressure index increased from 0.53 +/- 0.27 to 0.8 +/- 0.26 after stent deployment. The intraluminal pressure gradient decreased from 31.9 +/- 16.3 to 0.9 +/- 2.2 mm Hg after stent deployment. Complications included pseudoaneurysm (one), arteriovenous fistula (one), iliac perforation (one), groin hematoma (two), and occlusion (two). Follow-up arteriogram showed stenosis proximal or distal (n = 4) or within the stents (n = 4). These were treated with PTA or stents. Two patients required an aortobifemoral graft. Nine patients have died. Life table analysis showed a 1-, 3-, and 5-year primary and secondary cumulative patency of 87% +/- 5.9%, 74% +/- 8.2%, and 63% +/- 10% and 91% +/- 5.1%, 91% +/- 5.6%, and 86% +/- 7.6%, respectively., Conclusions: Palmaz stents, often required to salvage a PTA failure, appear to maintain overall patency at a high level. However, intimal hyperplasia and the progression of atherosclerotic disease may result in a need for additional procedures to obtain this favorable outcome.

Purpose: To determine the frequency with which treatment plans based on findings at magnetic resonance angiography (MRA) match those based on findings at conventional x-ray arteriography (XRA) in the evaluation of symptomatic lower extremity ischemia., Patients and Methods: Two-dimensional time-of-flight (TOF) MRA was performed in 42 patients undergoing XRA for evaluation of symptomatic lower extremity ischemia. The blind interpretations and treatment plans based on MRA findings were compared with those based on XRA findings, with use of XRA as the standard of reference., Results: For identification of hemodynamically significant stenosis or occlusion, the sensitivity and specificity of MRA was 100% and 23% for iliac segments, 100% and 82% for common femoral segments, 89% and 67% for superficial femoral segments, 100% and 88% for popliteal segments, and 92% and 91% for tibioperoneal segments, respectively. The treatment plan based on MRA findings matched that based on XRA findings in 41% of patients., Conclusion: For evaluation of symptomatic lower extremity ischemia, two-dimensional TOF MRA cannot be considered a reliable substitute for XRA in patients who lack contraindications to XRA.

Purpose: This retrospective review of femorodistal vein grafts was analyzed to determine the usefulness of various graft surveillance criteria., Method: The surveillance schedule involved evaluations at 1 month, every 3 months the first year, and then every 6 months. Salvage intervention or graft occlusion occurring within the next follow-up interval defined surveillance end points. One hundred two grafts (329 surveillance visits) had an ankle/brachial index (ABI). A duplex scanning-determined midgraft peak systolic flow velocity (PSFV) was available for 81 grafts (262 visits). Forty-eight grafts (137 visits) had both a PSFV and entire graft duplex scanning (EGDS) to determine stenosis greater than 50%, whereas 40 grafts (91 visits) had simultaneous ABI and EGDS., Results: When a greater than 15% decrease in ABI denoted an abnormal surveillance study result, a positive predictive value (PPV) of 24.3% and negative predictive value of 94.5% were noted. Similarly, a PSFV cutoff of less than 35 cm/sec demonstrated values of 26.3% and 94.2%, respectively. When an EGDS of greater than 50% stenosis or a PSFV of less than 35 cm/sec were the cutoff criteria, the PPV was 36.7% and negative predictive value 99.1%, whereas characterizing abnormal results further with ABI (> 15% decreases) increased the PPV to 83.3%., Conclusion: The combination of an EGDS, midgraft PSFV, and ABI provides optimal follow-up for our patients with a femorodistal vein graft.

Thirty-three in situ saphenous vein bypass grafts were performed using a conventional open technique (CI) while 31 in situ bypass grafts were performed using endovascular occlusion of side branches (EAI). Bypass grafts were performed from the femoral to the popliteal (n = 37) or a trifurcation (n = 27) artery for claudication (n = 7), rest pain (n = 14), or tissue loss (n = 43). Wound complications developed in 11 Cl and four EAI limbs. Postoperative hospitalization in CI and EAI patients was, respectively, 8.4 +/- 2.0 days and 4 +/- 1.6 days. Missed arteriovenous fistulas were noted in one CI and 17 EAI limbs postoperatively. At follow-up four (12%) CI and six (19%) EAI grafts were occluded or had undergone revision surgery. Based on life-table analysis CI and EAI cumulative patency rates at 18 months were 79% and 83%, respectively. Although this new technique (EAI bypass grafting) did not reduce operative time, it did decrease the length of surgical incisions and the duration of postoperative hospitalization (p < 0.001, Student's t test). Wound complications occurred less frequently in EAI limbs but the incidence of missed arteriovenous fistulas was significantly higher. These data suggest that EAI and CI patency is comparable. Ultimately long-term patency will be the crucial test for determining the utility of this new technique.

Purpose: The objectives were to transplant a venous valve into the popliteal vein of a canine insufficiency model that would maintain long-term function and then to measure the hemodynamic benefit of such a valve., Methods: Indexes of venous valvular function, including venous filling time, 90% of venous refilling time, and simulated ambulatory venous pressure, were measured in 11 greyhounds before intervention (Control) and after hind limb venous valvulotomy, which produces chronic venous insufficiency. Three weeks later a valve-containing segment of external jugular vein was transplanted to the popliteal vein with (n = 6) or without (n = 5) a distal arteriovenous fistula. The fistula was ligated in 4 to 6 weeks. Repeat venous indexes were obtained an average of 2 weeks after the last operative intervention. Gross anatomic inspection +/- duplex scanning performed before the animals were killed were used to distinguished normal from damaged valves., Results: Four of five simple valve transplants demonstrated scarring and/or thrombosis and the average venous filling time, ambulatory venous pressure, and 90% of venous refilling time were consistent with chronic venous insufficiency and/or obstruction. One fistula failed in the six valve distal arteriovenous fistula transplants, and that valve was incompetent. Analysis of the remaining five functional valves demonstrated venous filling time consistent with chronic venous insufficiency, normalization of ambulatory venous pressure, and 90% of venous refilling time between normal, and chronic venous insufficiency. These valves appeared normal., Conclusions: Popliteal vein valve transplant anatomy is preserved by an adjunctive distal arteriovenous fistula, and a competent valve transplant improves postexercise venous hemodynamics to approach those of a normal limb.

Purpose: This study evaluated an endovascular technique for occlusion of arteriovenous fistula when performing saphenous vein in situ bypass grafting., Methods: In 31 limbs femoropopliteal (17) or femorotibial (14) in situ bypass grafting was performed for claudication/aneurysm (4), rest pain (6), or tissue loss (21). A valvulotome was used for valve lysis. Saphenous vein branches were identified with angioscopy in 16 limbs or with fluoroscopy in the remainder. An electronically steerable endovascular catheter was used to deliver platinum coils into the venous tributaries to occlude them., Results: The maximal number of coils placed in any limb was nine. Most operations were performed with only a groin incision (length = 9.8 +/- 1.6 cm) and a distal incision (length = 16.8 +/- 6.5 cm). Wound complications occurred in four limbs, whereas four limbs developed localized superficial thrombophlebitis. The postoperative ankle-brachial index increased to a mean of 0.91 +/- 0.12. Postoperative duplex imaging revealed a missed arteriovenous fistula in 12 limbs. Two were surgically ligated, whereas the remainder were embolized in the radiology suite. Postoperative length of hospitalization was 4 +/- 2 days in uncomplicated cases. Follow-up revealed five graft occlusions. Occlusion occurred at 12 hours, 2 weeks, and 6, 14, and 15 months after operation. Although there were no perioperative deaths, two patients have died of unrelated causes., Conclusion: This endovascular technique of arteriovenous fistula embolization decreased the length of the surgical wounds, and patients were discharged 4 +/- 2 days in uncomplicated cases. The ultimate test of its efficacy, however, will be long-term functional results.

Continued study of a chronic deep venous insufficiency (CDVI) model allows optimal comparison with the human condition. This study evaluates the model's long-term stability, its lack of observed clinical effect, and a simulated exercise study as a physiologic estimate of normal hindlimb walking. The time to maximal ankle venous pressure after standing (VFT), and to 90% of the venous refilling time after electrical stimulation, quadripedal, or hindlimb walking (VRT90), and the minimal pressure after exercise (AVP) were measured up to 10 months after CDVI model creation. The animals' intravenous resting pressure was obtained after standing stationary on all four limbs. Analysis of variance was used to determine statistical significance where indicated. VFT, AVP, and VRT90 measurements demonstrated values consistent with CDVI in animals studied up to 10 months after model creation and were statistically different from control limb values (p < or = .002, n = 8). Animals studied during quadripedal walking showed no difference in resting pressure, AVP, and VRT90 between model and control limbs (n = 5). There was no statistical difference in AVP or VRT90 measured under conditions of stimulated exercise or bipedal walking; and both conditions produced hemodynamic changes consistent with CDVI (n = 5). This animal model is a reliable long-term CDVI hemodynamic model. The normal venous hemodynamics recorded during quadripedic walking may explain the lack of clinical sequelae observed in this model. Lastly, the method of simulated exercise used in this study is a reliable test that reflects physiologic measurements obtained during bipedal walking.

Fourteen cases of vascular injury during pancreatobiliary surgery have been treated at our institution. The patients' mean age was 49 years, and nine were males. Six operations were performed for chronic pancreatitis, six for cancer, and two for an inflammatory process. Operations included 11 pancreatic resections and one laparoscopic cholecystectomy, one sphincteroplasty, and one pseudocyst drainage. Vessels injured included the portal vein (7), superior mesenteric vein (6), superior mesenteric artery (3), hepatic arteries (4), splenic vein (3). Six patients experienced more than one vascular injury. In all but one case, the injury was recognized and repaired during the initial operation. Primary repair was possible in seven cases. Six cases utilized autogenous tissue for repair. The one unrecognized injury was a right hepatic artery ligation, and a delayed repair was not possible. Follow-up demonstrated two occlusions, one following a portal vein repair without clinical sequela and a superior mesenteric artery repair which resulted in a small bowel stricture. The one unrecognized hepatic artery injury resulted in necrosis of the proximal common hepatic duct. Vascular injury following pancreatobiliary injury tends to occur in the presence of pancreatitis or cancer with its associated dense adhesions and inflammatory process. The variable anatomy of this area contributes to vascular injuries. Immediate recognition of the injury and repair appears to yield excellent results.

Purpose: To evaluate functional post-radiotherapy arterial change in a select patient population., Methods and Materials: Thirty-five seminoma patients were identified in the Radiation Oncology departmental records at Indiana University Medical Center. In this group the ipsilateral pelvis is treated with the contralateral pelvis available for evaluation as a matched control. Additionally, this group is generally young and unlikely to have pre-existing vascular disease, and shows excellent radiocurability with historically standard radiotherapy. Nineteen patients volunteered for a noninvasive vascular evaluation which included: Doppler ultrasound, segmental leg pressures, pulse volume recordings, and post-exercise testing. Average age at treatment was 36 (range 14-68) with an average follow-up of 8.8 years (range 1-20) with five patients now over 15 years post-treatment. The majority of the patients received 2500-2600 cGy., Results: Three of 19 patients had abnormal vascular evaluations. Of these, two had bilateral abnormalities not felt to be solely associated with irradiation. The remaining patient showed both resting and post-exercise ipsilateral vascular abnormalities. Irradiation was the only identifiable etiologic agent for this patient's vascular abnormality., Conclusion: Subclinical vascular change attributable to low dose radiotherapy was identified in one of 19 patients (5%). Considering the radiocurability of seminoma patients this incidence is acceptable. In light of this slight, yet documented, arterial abnormality occurring with low dose radiotherapy, we recommend additional study of high dose radiotherapy patients to determine the incidence and morbidity of radiation-induced arteriopathy in this group.

This report describes a case of direct ureteral injury sustained during retroperitoneal vascular surgery. The diagnosis was delayed and treatment was complicated by infection. To address the patient's problem initially and then to consolidate our impressions, a literature review was undertaken. The conclusions from this review suggest that direct ureteral injury during vascular surgery is rare but most common during redo surgery, is just as likely to be missed as discovered during surgery, and when missed may be so for months. The diagnostic delay is caused by a varied and often misleading presentation, and a ureteral contrast study is the ultimate diagnostic tool. In these delayed cases the typical ureteral treatment is a stented ureteroureterostomy or nephrectomy. In the present case the patient was otherwise healthy; therefore an aggressive attitude to renal salvage was taken. This is a unique case of ileal conduit replacement of the damaged ureter for this specific situation. Five years after repair, renal function is stable without infectious complications. The current literature would suggest that the vascular graft may be left undisturbed if the urine is sterile. If infection is present, graft removal appears the standard of care and was successful in the present case.

The potential of drag reducing polymers (DRP) to selectively improve blood flow through clinically significant arterial stenoses was investigated. An artificial stenosis of the left common iliac artery in dogs decreased left femoral artery pressure by 25%. High-molecular-weight polyacrylamide (PA) or polyethylene oxide (PEO) were infused at a slow constant rate while we measured left and right common iliac artery blood flows and left and right femoral artery and vein pressures. As DRP were infused, left iliac artery flow (QL) increased early and then decreased to baseline values as flow began to increase in the right iliac artery. The peak increase in QL was 24 +/- 9% for PA and 46 +/- 19% for PEO and occurred before right iliac artery flow (QR) increased. As additional polymer was infused, QR increased to a maximum of 41 +/- 12 and 131 +/- 40% with PA and PEO, respectively. Femoral artery pressures and hindlimb resistances tended to decrease in both limbs but the only significant differences occurred in the right (nonstenosed) side when QR was elevated. This study provides the first evidence that low concentrations of DRP might be capable of improving blood flow through stenotic blood vessels without altering flow in normal vessels. Although DRP might represent a new class of compounds that could be utilized in the treatment of cardiovascular diseases, the degree of variation in individual responses is a concern, the exact mechanism of action is unclear, and information on pharmacodynamics is lacking.

Twenty-five patients were tested before and after carotid endarterectomy with resting and acetazolamide enhanced single photon emission computed tomography (SPECT) scans with hexamethyl propyleneamine oxine (HMPAO) or iofetamine hydrochloride I123 (123I labeled IMP), both widely available radiopharmaceuticals. Twenty preoperative SPECT studies were asymmetric, revealing focal or diffuse decreased perfusion reserve, and 13 also demonstrated infarcts. Five patients had symmetric (normal) studies. After carotid endarterectomy, 22 cases had changed flow distribution patterns. Usually improvement of reactivity ipsilateral occurred to the area operated on. In four, contralateral improvement was also found. Three of the patients who had preoperative symmetrical scans had increased ipsilateral reactivity after surgery indicating previous global loss of reactivity. Acetazolamide SPECT scans demonstrate a decreased perfusion reserve in 20 patients with carotid artery stenosis, indicating reduced perfusion and poor collateral circulation. Postoperative studies confirm improvement by demonstrating recovery of vascular reactivity in 84% of the patients. Acetazolamide enhanced SPECT scans may be helpful in providing objective evidence for selection of patients for carotid endarterectomy, especially in those who have an 80% carotid artery stenosis, but are asymptomatic.

Two-dimensional echocardiography can detect regional wall motion abnormalities resulting from myocardial ischemia produced by dobutamine infusion. In 60 patients undergoing elective aortic surgery (27 with aneurysms, 33 with occlusive disease), we evaluated the ability of dobutamine stress echocardiography to predict perioperative cardiac events. Echo images were obtained at rest and during incremental dobutamine infusion to a peak dose of 50 micrograms/kg/min, unless another test end point was reached (angina, heart rate greater than or equal to 85% of age-predicted maximum, significant ST segment depression, or new stress-induced wall motion abnormalities). Dobutamine stress echocardiography results were stratified as follows: group I, no wall motion abnormalities; group II, resting wall motion abnormalities unchanged with stress; group III, stress-induced worsening of resting wall motion abnormalities; group IV, new-onset wall motion abnormalities with stress. Twelve cardiac events occurred within the first 30 postoperative days: three cardiac deaths (5%), six nonfatal myocardial infarctions (10%), two patients with unstable angina (3.3%), and one patient with asymptomatic elevation of creatine phosphokinase MB isoenzymes without electrocardiographic changes (1.7%). Eleven events occurred in the 38 patients with an abnormal dobutamine stress echocardiograph (groups II to IV); in contrast, only one of 22 patients with a normal dobutamine stress echocardiograph (group I) had a cardiac event. These event rates (29% vs 4.6%) differed significantly (p less than 0.025). Dobutamine stress echocardiography is a new, safe, rapid, relatively low cost, noninvasive, nonexercise cardiac stress test for risk stratification before major vascular surgery.

This report evaluates the ability of a single competent (native or experimental) superficial femoral vein valve to correct canine hindlimb venous insufficiency. The time to maximal ankle venous pressure after standing (VFT) and to 90% of that time after exercise (VRT90), and the minimal pressure after exercise (AVP) were measured in 17 greyhounds before intervention, after only the superficial femoral vein valve remained (n = 5), and after complete lower limb venous valvulotomy (n = 17). Three weeks later, 12 dogs underwent a native (n = 4) or experimental (n = 8) autogenous venous valve transplantation. Immediately and at 3 weeks after transplantation, venous pressure measurements were obtained. The manual strip test confirmed valve competence at the time of sacrifice. Only one valve transplant became incompetent. Immediately after single superficial femoral vein valve construction, VFT, AVP, and VRT90 measurements were not significantly different from normal. Three weeks after transplantation the AVP measurements were consistent with an insufficient venous system, whereas the VRT90 measurements were between and statistically different from both the control and totally incompetent system (p less than 0.05). After the native valve but not the experimental valve transplantations VFT normalized. These data suggest that insertion of a single competent superficial femoral vein valve into an incompetent lower limb venous system corrects venous pressure measurements initially but soon provides only a partially competent system. The experimental valve, although competent, is less responsive than a native valve.

Historically, mesenteric venous thrombosis (MVT) has been found during laparotomy or at autopsy. Improvements in computed tomography (CT) and ultrasound (U/S) may identify patients earlier in their clinical course. How has this altered the treatment strategy of the authors? This 10-year retrospective study of acute MVT consisted of 12 men and three women (average age 43). Presenting signs and symptoms were nonspecific in 10/15 patients resulting in multiple diagnostic tests. All CT scans (10) and angiograms (4) revealed mesenteric clot. U/S exams detected clot in 6/9 patients. The remaining five patients exhibited clinical signs requiring operations rather than diagnostic studies. The only consistent laboratory abnormality was an elevated white blood cell count in 12/15 patients. Management of MVT varied. Five patients, heparinized once the diagnosis was made, did not experience dysfunction from MVT. Ten patients were not initially treated with heparin and were divided into three groups. Three patients received neither heparin nor surgery and have had no sequelae. MVT contributed to the death of two patients. The remaining five patients were diagnosed in the operating room following bowel resection. Two of these patients received postoperative heparin and had a favorable outcome. Two of the three patients not heparinized after surgery suffered additional bowel infarction. MVT can present as nonspecific abdominal pain, but also as peritonitis requiring operation. CT and U/S can identify patients with early MVT. It appears that heparin has both a primary therapeutic role in early disease and a postoperative adjunctive role in advanced disease. With such care, these patients can expect an acceptable prognosis (86% survival).

From 1983 to 1990, nine patients with combined hypogastric (HA) and profunda femoral arterial (PFA) occlusive disease presented with five nonhealing hip disarticulations, three nonhealing above-the-knee amputations, perineal necrosis in six patients, buttock necrosis in four patients, visceral ischemia in two patients, and lumbosacral spinal ischemia in one patient. Obviously some patients had more than one regional complication. Five patients died from complications of HA/PFA ischemia. Survivors included two patients who required a hemipelvectomy, one patient who required an axillary-to-hypogastric artery bypass graft for stump salvage, and one patient who survived despite lumbosacral paralysis and complete cystectomy. The 56% mortality and 100% morbidity emphasize the critical significance of combined hypogastric/profunda femoral artery circulatory compromise. Efforts should be made to preserve or re-establish the HA and/or PFA circulation whenever possible. A hemipelvectomy may be required to allow the wounds to finally heal. Furthermore, the certainty of an above-the-knee amputation healing is not present in these patients; therefore, a hemodynamic assessment of the healing potential of an above-the-knee amputation is required.

Both in vivo and mathematical models of venous hypertension were used to evaluate the hemodynamic effects of 4, 6, 8, and 10 mm diameter cross-femoral venous bypass grafts (CFBs). Eighteen grafts (length 138 +/- 3.4 mm) were tested in paired sequential fashion (four grafts, 4 and 8 mm; five grafts, 6 and 10 mm) in nine greyhounds (femoral vein diameter, 7.7 +/- 0.09 mm). Bilateral hindlimb venous pressures and flows were measured before and after unilateral iliofemoral venous ligation, 30 minutes after CFB insertion, and for 5 minutes after venous flow augmentation induced by stimulated muscle contraction. CFBs of all sizes were equally effective at relieving the occlusive venous hypertension at rest. Muscle contraction elevated venous pressure in all ligated hindlimbs (p less than 0.0001); however, the pressure returned to baseline by 3 minutes in dogs with 6, 8, and 10 mm grafts but remained elevated (p less than 0.05) with the 4 mm grafts even after 5 minutes. Peak graft flow (first 90 seconds after contraction) was significantly greater through the 8 mm grafts than through the 4 mm grafts (p less than 0.01), although no difference was noted in flow rates between 6 and 10 mm grafts. The pressure gradient across the graft as predicted by the mathematic model for 6 to 10 mm conduits was less than 5 mm Hg for flows up to 1000 ml/min, although the pressure gradient of the 4 mm graft exceeded 5 mm Hg at 200 ml/min and approached 30 mm Hg at 1000 ml/min. Therefore, data from both canine and mathematical models agreed that, at rates approximating human resting flow (1000 ml/min), no adverse short-term hemodynamic consequences result from CFB conduits of 6 to 10 mm diameter.