Faculty Bibliography

Little attention has been given to superficial thrombophlebitis and particularly to lesser saphenous vein thrombophlebitis (LSVT) by vascular surgeons. A prospective nonrandomized study was conducted to assess LSVT's potential association with deep venous thrombosis (DVT) as well as its natural history. Between January 1994 and December 1995, the authors reviewed 33 cases of LSVT detected by duplex scanning in 32 patients at their institution's vascular laboratory. Combined LSVT/DVT was treated with heparin and warfarin. LSVT alone or LSVT plus greater saphenous vein thrombophlebitis (GSVT) were treated with local warm compresses and nonsteroidal antiinflammatory drugs. Follow-up scans were obtained in 23 of the 32 patients and ranged from 2 weeks to 18 months after diagnosis of LSVT. Thirty-one patients had unilateral LSVT and 1 patient had bilateral LSVT. Isolated LSVT was found in 9 patients (28%), LSVT combined with DVT occurred in 21 patients (65.6%), and 2 patients had LSVT/GSVT. LSVT was contiguous with DVT in 15 patients, and in 5 patients it was noncontiguous. Within 3 months, 9 of 16 patients (56%) with LSVT/DVT had complete or partial resolution of their LSVT, and 1 (14%) of the 7 patients with LSVT and LSVT/GSVT had improved. Within 18 months, 13 of 16 patients (81%) with LSVT/DVT had complete resolution of their thrombus while only 3 of 7 patients (43%) with LSVT and LSVT/GSVT had resolved. These data show that LSVT is more often associated with DVT (65.6%) than previously believed. While most LSVT will improve in 18 months, those associated with DVT will resolve sooner. Whether anticoagulation accounted for this difference remains to be proven.

PURPOSE: Glycine has a protective effect in renal and skeletal muscle ischemia. The purpose of this study was to evaluate the effect of glycine in mesenteric ischemia and reperfusion injury in a rat model. METHODS: Twenty-four anesthetized male Sprague-Dawley rats were subjected to 1 hour of mesenteric ischemia followed by 2 hours of reperfusion. Control animals received normal saline solution intravenously at 0.01 mL/g of body weight/h during ischemia and reperfusion. Treated animals received glycine at 0.5, 0.75, or 1.0 mg/g of body weight, dissolved in saline solution and infused at 0.01 mL/g/h for 2 hours. Animals were killed at the end of the experiment, and proximal, middle, and distal segments of the small bowel were isolated. Sections of the segments stained with hematoxylin-eosin were subjected to histologic examination (as per modified Chiu grading system) and morphometric analysis consisting of measurement of bowel wall, muscularis and mucosal thickness, epithelial coverage, and villar circumference. Isometric tension responses to electrical stimulation (10, 30, 50, 100 Hz), high doses of potassium (120 mmol/L), and carbachol (0.1, 0.5, 1.0, 5.0 micromol/L) were recorded in a multimuscle chamber. Statistical analysis was performed with unpaired t test and one-way analysis of variance. RESULTS: The middle and distal segments of the small bowel in glycine-treated animals showed better histologic grade compared with saline solution-treated control rats (P <.05). At morphometric analysis, total thickness, mucosal thickness, and villar circumference ratio were well preserved in the middle and distal segments of the small bowel in the glycine-treated group (P <.05). No significant differences were observed in the proximal bowel segments between glycine-treated and control animals, because the proximal segment was not subjected to much ischemia. No differences were noted in percentage of epithelial coverage. Isometric tension responses evoked by electrical stimulation were greater (P <.05) in the middle and distal segments treated with glycine as compared with control segments. Carbachol-evoked contractions were stronger (P <.05) in the small bowel segments of animals treated with glycine. The responses evoked by 120 mmol/L of potassium were stronger in the distal segments of the small bowel in the glycine-treated group (P <.05). This cytoprotective effect of glycine was not dose-dependent. CONCLUSIONS: Glycine improved mucosal viability in the ischemia and reperfusion injury rat model. Mucosal thickness and villous circumference ratio were reliable objective parameters for evaluation of intestinal ischemia injury. Glycine improved the contractile responses of the bowel segments also, probably by altering the physiologic mechanisms underlying force generation. Further studies are required to elucidate the mechanism of the cytoprotective action of glycine.

OBJECTIVE: Upper extremity embolic complications of occluded axillofemoral bypass grafts are infrequent. However, traditional management of dissection of axillary anastomosis for removal of the stump can be challenging. We report two patients with critical upper extremity ischemia secondary to stump syndrome and its successful management with endovascular techniques. METHODS: One hundred fifty-two patients underwent axillofemoral bypass grafting over 10 years from 1991-2001. Two patients from this series had acute ischemia involving the ipsilateral upper extremity of occluded axillofemoral bypass graft. Duplex ultrasound scans revealed occlusion of the axillofemoral bypass graft and acute occlusion of ipsilateral upper extremity arteries. Both patients underwent brachial artery exploration and embolectomy. Completion angiograms revealed persistent axillofemoral bypass graft stump as the source of embolus. The stump was obliterated with a 10-mm/40-mm Wallgraft introduced through the same arteriotomy made for brachial embolectomy. Transesophageal echocardiography and magnetic resonance angiography of the arch and great vessels were performed to exclude other sources of origin for the embolus. RESULTS: Both patients remained symptom-free and with patent stent grafts, as seen on duplex scans at 3, 6, and 9 months of follow-up. CONCLUSIONS: Upper extremity embolism is a rare complication after occlusion of axillofemoral bypass grafts. The endovascular approach to obliterate the stump of occluded axillofemoral bypass grafts is minimally invasive and an effective alternative treatment of this rare condition.

PURPOSE: We have previously demonstrated that glycine has a protective effect in mesenteric ischemia/reperfusion (I/R) injury. The purpose of this study was to elucidate the molecular mechanisms of the cytoprotective action of glycine. Because oxidative stress in I/R injury can lead to apoptosis, we examined the role of glycine in modulating the apoptotic signals in a rat mesenteric I/R injury model. METHODS: Twenty-four anesthetized male Sprague-Dawley rats were subjected to 1 hour of mesenteric ischemia followed by 2 hours of reperfusion. Control animals (n=6) received normal saline intravenously at the rate of 0.01 mL/g/h during the ischemia and reperfusion period. Treated animals divided in 3 groups (n=6 in each) received glycine at a dose of either 0.5, 0.75, or 1.0 mg/g, infused at the rate of 0.01 mL/g/h during the reperfusion period. Animals were killed at the end of the experiment, and proximal, middle, and distal segments of the small bowel were harvested for histopathology, TUNEL assay, and immunohistochemistry. Expression of apoptosis-related molecules, bcl-2, bax, caspase-3, death receptor, Fas, and death substrate, poly (ADP-ribose) polymerase (PARP) were studied. RESULTS: In glycine-treated animals, the middle and distal segments of the small intestine were well- preserved and showed better histologic grade and morphometric parameters as compared with saline controls (P<.05) in a dose-independent manner. There was increased apoptosis in saline controls as compared to the treated group (P<.01). Pro-apoptotic bax and caspase-3 were downregulated, whereas bcl-2 was upregulated in the glycine-treated animals (P<.02). Increased expression of death receptors and cleavage of PARP was observed in saline controls as compared to treated groups (P<.05). No significant differences were noted between the proximal bowel segments of treated and control animals. CONCLUSIONS: These data support the concept that I/R causes formation of death- inducing signal complexes, which may activate the sequential cleavage of caspases and death substrates. We have demonstrated that one of the mechanisms of the protective effect of glycine is the downregulation of the death-inducing signals and abrogation of the apoptotic cascade in this I/R injury model.

BACKGROUND: We have previously demonstrated that programmed cell death, proteolytic activity, and inflammatory infiltrate in the aneurysmal wall may have a role in the pathogenesis of popliteal artery aneurysms (PAA). This investigation examines the expression of a cell death-promoting molecule, a cysteine protease, YAMA/CPP-32 in a series of PAA specimens. METHODS: Twenty PAA specimens were obtained from patients undergoing elective surgical repair. Normal controls were popliteal arteries obtained from patients without PAA who were undergoing infrainguinal bypass surgery (n = 8). Standard histochemistry techniques were used to assess inflammatory infiltrates in PAA. Expression of apoptosis-promoting molecule, CPP-32, vascular smooth muscle cells (VSMC), macrophages, and T lymphocytes was detected by immunohistochemistry. RESULTS: There is a conspicuous disruption and fragmentation of elastic lamellae and increased inflammatory infiltrate in the PAA as compared with normal arteries. As compared with normal popliteal artery tissues, the PAA demonstrated large number of cells immunopositive for CPP-32 (60.45 +/- 4.25% P < 0.05). This study revealed significantly increased expression of CPP-32 in the T-cell population of the PAA as compared with the other cells (P < 0.01). Dual immunolabeling and investigation of serial sections demonstrated that co-expression of CPP-32 was maximum in the CD8+ subset (37 +/- 3.3% of the total CPP-32 immunoreactive cells identified). CONCLUSIONS: The data emphasize that the inflammatory infiltrate in the PAA walls has a significant role in the pathogenesis of this vascular disorder. Cells expressing death-promoting molecules are present in large numbers and are predominantly T lymphocytes in PAA. In addition to compromising the mechanical integrity of the vessel wall, apoptosis in the inflammatory infiltrate may contribute to the production of cytokines, activation of other signaling molecules such as stress proteins that could eventually favor PAA development.

Contrast arteriography (CA) is the gold standard preoperative imaging modality for patients with chronic and acute lower limb ischemia. We have previously shown that high-quality DUAM can safely replace CA in patients with chronic ischemia. The goal of this study was to investigate whether DUAM can also be used effectively in the setting of acute ischemia. From January 1998 to February 2001, 68 patients were admitted to our institution with 87 instances of acute lower limb(s) ischemia and underwent 87 operations. There were 34 men and 34 women whose age ranged from 51 to 95 years (mean 72 +/- 12.5). There were 44 cases of acute arterial occlusions and 43 cases of bypass graft thromboses. In the former group the most proximal occluded site based upon duplex was the aorta in 1 case, common iliac in 4 cases, external iliac in 15 cases, and infrainguinal arteries in 24 cases. In the latter group, there were 4 suprainguinal grafts, 24 bypasses to the popliteal artery, and 15 bypasses to infrapopliteal arteries. All patients had DUAM as their initial diagnostic study. The duplex protocol varied according to the pulse exam. In patients with a good femoral pulse but absent popliteal pulse, attempts were made to visualize the ipsilateral femoral-popliteal segment and the proximal third of the infrapopliteal arteries. This was extended to the pedal arteries in cases of proximal occlusion. When the femoral pulse was absent the protocol included visualization of the distal aorta, bilateral iliac, and common femoral arteries. This exam was extended into the deep and superficial femoral-popliteal segments in cases of proximal occlusion. None of these cases had preoperative or prebypass CA. Intraoperative arterial pressures to confirm the adequacy of the inflow tract and completion arteriography to assess the runoff were performed in 78% of the cases at the end of the procedure. This initial experience suggests that high-quality DUAM may replace CA in patients with lower limb ischemia. DUAM provides a reliable assessment of the inflow and outflow arteries even in very low-flow situations. In addition, DUAM can identify the cause of the arterial occlusion, thereby making therapy more effective and less time consuming.

OBJECTIVE: We undertook this study to determine whether popliteal artery aneurysm diameter correlates with initial symptoms and presence of associated occlusive disease. METHODS: Duplex arteriography before infrainguinal revascularization in 500 lower extremities enabled diagnosis of 34 popliteal aneurysms in 25 patients (24 male, 1 female) over the last 4 years. Fourteen patients (41%) had no symptoms (group 1) and 20 (59%) had symptoms (group 2) of severe claudication (n = 8), acute ischemia (n = 6), rest pain (n = 2), and tissue loss (n = 4). We compared clinical presentation with popliteal artery diameter, prevalence of thrombosis, and presence of associated occlusive disease. RESULTS: Popliteal artery aneurysm diameter averaged 2.8 +/- 0.7 cm (range, 1.8-4.5 cm) in group 1 and 2.2 +/- 0.8 cm (range, 1.3-4.0 cm) in group 2 (P <.03). Popliteal aneurysm thrombosis was present in 7 of 20 limbs in group 2. Four of these patients also had ipsilateral superficial femoral artery thrombosis. Evaluation of the infrapopliteal arteries in group 1 showed three-vessel runoff in 7 limbs, two-vessel runoff in 3 limbs, one-vessel runoff in 2 limbs, and no vessel runoff in 2 limbs. However, all infrapopliteal arteries were either occluded or significantly stenotic in 14 limbs (70%). In group 2, one-vessel runoff was observed in 5 limbs, and two-vessel runoff in 1 limb. CONCLUSIONS: Smaller popliteal artery aneurysm was associated with higher incidence of thrombosis, clinical symptoms, and distal occlusive disease. Liberal use of duplex scanning in this setting may have accounted for the increased awareness that small popliteal artery aneurysms can thrombose and present with severe ischemia.

PURPOSE: It is believed that cerebral hyperperfusion syndrome (CHS) is caused by loss of cerebral autoregulation resulting from chronic cerebral ischemia and that factors including increased intraoperative cerebral blood flow, ipsilateral or contralateral carotid disease, and postoperative hypertension may cause CHS. We describe our experience with CHS, which diverges from published reports. MATERIALS AND METHODS: From March 2000 to February 2002 we performed 455 carotid endarterectomy (CEA) procedures in 404 patients at our institution. CHS developed 1 to 8 days (mean, 3.2 +/- 2.5 days) postoperatively in 9 patients (2%), 6 women and 3 men, whose age ranged from 52 to 84 years (mean, 69 +/- 8 years). Indications for surgery in 8 patients without neurologic symptoms were ipsilateral internal carotid artery (ICA) stenoses ranging from 70% to 99% (mean, 80% +/- 7%); the remaining patient had an ipsilateral stroke, with good clinical recovery, 7 weeks before CEA. Only 1 patient had significant contralateral ICA stenosis (70%). However, 5 patients had undergone contralateral CEA within the previous 3 months. CHS symptoms were severe headache in 5 patients, seizures in 3 patients (1 stroke), and visual disturbance and ataxia in 1 patient. All 404 patients (455 cases) underwent intraoperative and early (2 weeks) postoperative carotid artery duplex scanning. The 9 patients with CHS also underwent carotid artery duplex scanning at the time of the neurologic event. RESULTS: Mean intraoperative ICA volume flow (MICAVF) in the 9 CHS cases was not significantly different from that in the other 446 cases (170 +/- 47 mL/min and 182 +/- 81 mL/min, respectively). However, mean ICA volume flow (481 +/- 106 mL/min) and peak systolic velocity (PSV) (108 +/- 33 cm/s) for the 9 CHS cases measured at onset of symptoms were higher than those for the remaining 446 cases (267 +/- 87 mL/min and 80 +/- 26 cm/s, respectively) (P <.01). Of the 9 patients with CHS, only 3 had systolic blood pressures more than 160 mm Hg at onset of symptoms. Severity of ipsilateral and contralateral ICA stenoses was not significantly different between the 9 CHS cases and the remaining 446 cases. CONCLUSIONS: These data do not corroborate the common belief that CHS occurs preferentially in patients with severe ipsilateral or contralateral carotid disease, increased intraoperative cerebral perfusion, or severe hypertension. Recently performed contralateral CEA (<3 months) appears to be predictive of CHS.

PURPOSE: The morbidity associated with contrast-based diagnostics performed for preoperative evaluation prior to vascular intervention ranges from 1 to 21%. These complications range from minor hematomas to death. However, these exams are commonly felt to be a necessary step to completely evaluate the arterial tree before intervention is undertaken. Since this has varied from our experience, we reviewed our experience with repair of abdominal aortic aneurysms (AAAs), carotid endartectomy (CEA), and lower extremity revascularization performed without preoperative contrast studies. MATERIALS AND METHODS: During the last 10 years, we have performed 184 elective AAA repairs with abdominal-pelvis CAT scan without intravenous contrast as a preoperative study. During this same period of time, 903 CEAs were performed in 810 patients based solely on duplex ultrasonography or in combination with magnetic resonance angiography in cases where duplex ultrasonography was inconclusive (53 cases). Finally, over the last 30 months, we have performed 485 revascularizations in the lower extremity based solely on duplex ultrasonography mapping. Direct visualization of all major arteries from the distal aorta to the pedal vessels was performed using duplex imaging. Both the carotid duplex imaging and lower extremity duplex imaging were confirmed to have greater than 95 % positive predictive value during an initial phase of 50 cases confirmed with MRA and contrast angiography respectively. RESULTS: All cases of venous anomalies such as retrocaval left renal vein or left sided inferior vena cava in AAA patients were accurately identified and confirmed by intraoperative findings. No cases of horseshoe kidney were identified. Despite the presence of diminished femoral pulses in six patients, aortic reconstructions were performed with only duplex imaging. The 30 day mortality of AAA patients was 5% for elective repairs. In addition, no gross differences were appreciated with intraoperative findings of CEA as compared to preoperative duplex findings. However, in 5 cases CEA could not be performed due to extension of the lesion well above the available surgical exposure. The 30 day mortality of the CEA patients was 0.7% and the incidence of postoperative stroke or transient ischemic attack was 0.7%. Finally, in two early cases of lower extremity revascularization, the distal anastomosis was placed proximal to a lesion. This was appreciated during the procedure and corrected with a jump graft in each case. CONCLUSIONS: These data suggest that AAA repair, CEA, and lower extremity revascularization can be performed without contrast based preoperative studies and without compromise to evaluation of disease, patient safety or patency of bypass grafts.

The TrapEase filter is a permanent, symmetric nitinol filter that can be deployed through a low-profile sheath. Although the TrapEase is enjoying an increasing market share of inferior vena cava (IVC) filters, there are still limited clinical follow-up data on its use. This study is a retrospective review of 189 consecutive infrarenal TrapEase filters placed at our institution. The study included 80 men and 109 women, with an average age of 73 years (24-102). The most common indication for filter placement was a contraindication to warfarin. In total, 13% of the patients were treated with warfarin. The filter was successfully deployed in all cases, via the right femoral vein in 57% of the patients, via the left femoral vein in 32%, and via the right internal jugular vein in 11%. Follow-up studies were performed as clinically indicated. During the investigation, there were three cases of IVC thrombosis (1.5%) and one case of retroperitoneal hemorrhage potentially caused by filter placement. Two of the thrombosis cases resulted in serious sequelae. This study also represents the first report of a symptomatic pulmonary embolism (PE) after TrapEase filter placement. While this investigation does demonstrate a low overall complication rate of this new device, it raises the concern of an increase in IVC thrombosis rate.