bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymptomatic Popliteal Vein Aneurysms
Authors: Labropoulos Nicos , Volteas Spiridon K. , Giannoukas Athanasios D. , Touloupakis Emanouel , Delis Kostas , Nicolaides Andrew N. 
Published: June 2007

Popliteal vein aneurysms represent a rare vein abnormality. There is agreement on the etiology, symptomatology (thromboembolism), and diagnosis (color duplex scanning). Surgery is the treatment of choice in symptomatic cases, but management in asymptomatic cases remains uncertain. Seven cases (5 women and 2 men with a mean age of fifty-nine years) of asymptomatic popliteal vein aneurysms are presented. The diagnosis and follow-up were made by color flow duplex imaging (CFDI). All aneurysm were of a saccular type, fully compressible, without evidence of thrombus in the sac, and with a maximal diameter ranging from 2.0 to 2.8 cm. In all but 1 case the popliteal valve was located in the aneurysmal sac and minor reflux was detected. Superficial vein incompetence was found in 6 patients, whereas in the seventh patient reflux was found in the superficial femoral vein. No treatment was offered and close surveillance with CFDI every four months was performed. So far, all patients remain asymptomatic over a period of two months to two years. Asymptomatic cases may remain without treatment under close surveillance with CFDI and regular clinical follow-up.
Input Impedance of Revascularized Skeletal Muscle, Renal, and Mesenteric Vascular Beds
Authors: Schwartz Lewis B. , Purut Cemil M. , Craig Damian M. , Smith Peter K. , Mccann Richard L. 
Published: June 2007

Input impedance describes the relationship between pressure and flow in a vascular system and, hence, characterizes the outflow bed. The purpose of this investigation was to measure input impedance spectra in vascular reconstructions of skeletal muscle, renal, and mesenteric beds. Input impedance was measured in 107 vascular reconstructions in 96 patients. Reconstructions were performed at the aortofemoral/aortoiliac (AF, n = 20), femoropopliteal (FP, n=18), femorodistal (FD, n=41), infrapopliteal-inframalleolar (IM, n = 6), renal (REN, n = 16), or mesenteric (MES, n= 6) level. Grafts were constructed from autologous vein in all cases except AF bypasses in which bifurcated woven Dacron grafts were employed. Input impedance was measured intraoperatively after reperfusion. For impedance calculation, simultaneously acquired intraluminal pressure (transducer-tipped pressure catheter) and blood flow (electromagnetic probe) waveforms of ten-second duration were digitized at 200 Hz and subjected to Fourier transformation in near real-time. AF grafts exhibited the highest blood flow (443 ± 72.8 mL/minute) followed by MES (300 ± 30.4), REN (172 ± 43.9), FP (91.6 ± 20.0), FD (59.3 ± 5.09), and IM grafts (22.4 ± 5.44 mL/minute). A similar (inverse) trend was observed with respect to resistance (Rin), ie, MES≈AF<REN<<FP<FD<<IM(15.7 ± 2.2=23.7 ± 6.5<69.2 ± 12.2 < < 120 ± 31.9 < 137 ± 13.0 < < 337 ± 75.8 x 103 dyne•s•cm-5). As expected, AF grafts exhibited the lowest characteristic impedance (Z0 3.5 ± 0.8 x 103 dyne•s•cm-5). However, the Z0 of REN (20.2 ± 3.7 x 103 dyne•s•cm-5) grafts exceeded that of FP and MES grafts (10.5 ± 1.1 and 12.4 ± 4.0 x103 dyne•s•cm-5) and more closely approximated that of FD (22.2 ± 2.2 x 103 dyne•s•cm-5). The highest Z0 was seen in IM grafts (42.1 ± 15.8 x 103 dyne•s•cm-5). Therefore, the highest ratios of Z0/Rin were observed with MES (0.75 ± 0.23) and REN (0.33 ± 0.04) grafts as compared with the other groups (AF 0.23 ± 0.03, FP 0.12 ± 0.13, FD 0.19 ± 0.02, IM 0.16 ± 0.06). As expected, Rin of vascular reconstructions follows the general trend of MES ≈ AF < REN < < FP < FD < < IM. However, examination of the high-frequency components of the impedance spectra reveals that Z0 follows a different pattern, AF < FP MES < FD ≈ REN < < IM and the ratio of ZO/Rin is highest in REN and MES vascular beds compared with skeletal muscle beds. Thus, although the REN and MES beds are “privileged” (ie, maximally dilatated with low arteriolar tone), the intrinsic properties of the graft and larger blood vessels are no different than those of a femorodistal bypass.
Spontaneous Carotid Artery Dissection: Case Reports and Review of the Literature
Authors: Calaitges John G. , Deshmukh Narayan 
Published: June 2007

A review of the authors' experience with spontaneous carotid artery dissections and a comparison of their management strategies and outcomes with a review of the recent literature are presented. A retrospective chart analysis revealed 5 cases over the past nine years. All were treated in a conservative fashion. Two underwent anticoagulation, 2 received antiplatelet therapy, and 1 was merely observed. Their ages ranged from thirty-eight to eighty-three and all were men. Four of the 5 (80%) went on to an uneventful recovery. One patient receiving anticoagulation developed total occlusion of the left internal carotid artery associated with an acute stroke. Angiography is the gold standard for diagnosis, but the role of duplex ultrasound for diagnosis and follow-up has strengthened. Of patients with spontaneous carotid artery dissection, 85-90% have an uneventful recovery, and surgical intervention is rarely indicated.
Intraarterial Adenosine Administered During Reperfusion Preserves Endothelium-Dependent Relaxation in the Rabbit Hindlimb
Authors: Farooq Michael M. , Freischlag Julie A. , Carlsen Brian T. , Cambria Robert A. , Seabrook Gary R. , Towne Jonathan B. 
Published: June 2007

Consumption of adenosine triphosphate (ATP) during ischemia leads to the failure of cell membrane ATP-dependent ion pumps, cell lysis, and activation of the inflammatory cascade, which contributes to endothelial injury during reperfusion. Adenosine is a lipidsoluble precursor in ATP metabolism that may be depleted during reperfusion, exacerbating this injury. The purpose of this study was to examine the effect of adenosine administration with reperfusion on endothelium-dependent relaxation in the rabbit superficial femoral artery. New Zealand white rabbits underwent 3 hours of complete unilateral hindlimb ischemia followed by 2 hours of reperfusion. Animals received an intraarterial infusion of adenosine (0.35 mg/kg/min) or an equivalent volume of normal saline (1 cc/min) during the first 20 minutes of reperfusion. A sham group underwent aortoiliac collateral ligation and 5 hours of anesthesia without ischemia. A control group underwent immediate superficial femoral artery explantation with no collateral ligation or prolonged anesthesia. The superficial femoral arteries were explanted and suspended as 3 mm segments upon isometric force transducers within organ bath chambers. Contraction was evaluated with potassium chloride (KCl) and maximal norepinephrine (NE). Acetylcholine (Ach) relaxation was determined after NE submaximal contraction. No difference in contractile response to KCl was observed among the four groups. A significant increase in contraction to maximum NE was observed for vessels in the adenosine group (P<0.05). A significant increase in relaxation was noted over four consecutive doses of Ach administered to vessels from the adenosine, sham, and control groups when compared with the saline group (P<0.05). Adenosine administered during reperfusion preserved endothelium-dependent relaxation after ischemia and reperfusion in the rabbit superficial femoral artery. Adenosine may act as a substrate for ATP resynthesis and maintain cellular integrity during reperfusion. This form of pharmacologic therapy may prove clinically useful in the treatment of extremity ischemia/reperfusion injury.
Endovascular Surgery: An Integral Component of Treatment for Infected Aortobifemoral Bypass Grafts
Authors: Elmore James R. , Franklin David P. , Youkey Jerry R. 
Published: June 2007

Endovascular reconstruction may be used alone or in combination with standard vascular techniques in dealing with infected grafts. This case report concerns a 53-year-old man who presented with sepsis 3 years after undergoing aortobifemoral bypass. The bypass was performed after two failed angioplasties. The proximal anastomosis was performed in an end-to-side fashion. One year prior to presenting with sepsis, the patient developed acute myelogenous leukemia and underwent chemotherapy with subsequent remission. Eight months later, the patient developed low-grade fever and chills and was treated for pulmonary infection. Persistent mild symptoms prompted a Gallium scan that raised the possibility of an infected aortic graft. Subsequent computed tomography (CT) scan, magnetic resonance imaging (MRI), and Indium scan were normal. Admission was prompted when he presented with biopsy-documented septic emboli to the right leg. Repeat CT scan suggested aortic graft infection localized to the proximal graft segment. Operative repair included a right common femoral endarterectomy, a right iliac balloon angioplasty, insertion of a right iliac Wallstent, and a right-to-left femoral-femoral polytetrafluoroethylene (PTFE) bypass. The well-incorporated femoral graft limbs were detached and the groins closed. Abdominal exploration identified a jejunal-aortic graft erosion with a localized abscess. The infected graft was removed and the aortotomy repaired with a patch fashioned from an endarterectomized portion of the occluded left external iliac artery. Small bowel resection with primary anastomosis and omental flap completed the operation. Four days postoperatively, the Wallstent required further expansion with an open balloon angioplasty to establish palpable pedal pulses. The patient recovered uneventfully and received a total of 6 weeks of broad-spectrum intravenous antibiotics. This case illustrates the use of adjunctive endovascular techniques in handling difficult vascular graft infections and stresses their importance as an integral component of the vascular surgeon's armamentarium.
Outcome of the Contralateral Carotid Artery in Patients Having Undergone Ipsilateral Carotid Endarterectomy: Results of Selective Management
Authors: Eklof Bo G. , Kistner Robert L. , Masuda Elna M. , Wong Howard P. 
Published: June 2007

Purposes: To evaluate the natural history of the carotid artery in patients who have undergone endarterectomy of the opposite carotid artery, study its relation to new neurologic events by clinical follow-up and serial duplex scanning, review the literature for management guidelines at present, and evaluate the impact on these guidelines from recently published prospective, randomized trials. Methods: A retrospective study of 275 consecutive patients who underwent carotid endarterectomy (CEA) from December 1985 through December 1992. Results: Of 275 patients, 115 were excluded (lost to follow-up, preoperative contralateral carotid occlusion, perioperative death or stroke) leaving 160 patients as the final study group. Progression of contralateral stenosis from <50% to 50-79% occurred in 13/113 patients (11.5%), all asymptomatic; from 50-79% to 80-99% in 10/38 patients (26.3%), (two symptomatic-one transient ischemic attack [TIA] and one stroke-<50% to 80-99% in one patient who was asymptomatic); no patient progressed to total occlusion. All nine patients with an initial contralateral stenosis 80-99% remained asymptomatic prior to subsequent CEA. Neurologic events referable to the contralateral carotid distribution occurred in 10 patients of 160 (6.3%) at a mean of 12.8 months after initial surgery, six TIAs and four strokes, none of which was heralded by TIA. Thus 24 patients showed progression of stenosis, with two (8.3%) manifesting symptoms. Of the other 136 patients without progression of stenosis, eight (5.9%) developed symptoms. Conclusions: Our data and a review of the literature does not support an aggressive approach to the contralateral carotid artery stenosis. Based on NASCET and ACAS, however, new guidelines for management are suggested.
Ultrasound-Guided Compression for Treatment of latrogenic Arteriovenous Fistulae
Authors: Massie Mitchell T. , Rohrer Michael J. , Cardullo Paul A. , Cutler Bruce S. 
Published: June 2007

Pseudoaneurysms and arteriovenous fistulae (AVF) are the two most common vascular complications following percutaneous common femoral artery cannulation. Encouraged by favorable results using ultrasound-guided compression (UGC) to treat iatrogenic femoral pseudoaneurysms, we prospectively evaluated UGC for the treatment of iatrogenic AVF. AVF were identified in 13 patients between September 1, 1995 and March 31, 1997. Eleven agreed to a trial of UGC. UGC was continued for 60 minutes with color-flow duplex scanning to monitor the adequacy of compressions. There were 13 attempts to thrombose AVF in 11 patients. Two patients had unsuccessful UGC while anticoagulated. In both cases, a second UGC was unsuccessful after correction of the coagulation profile. Two types of AVF were identified. A “direct” communication between the adjacent walls of the artery and vein was present in 10 patients. The other patient had a 2-cm “indirect” fistulous tract between the artery and vein. Direct communications were associated with peak spectral flow velocities ranging from 128 to 500 cm/sec (mean, 331 cm/sec), whereas the peak spectral flow velocity in the patient with the fistulous tract was only 70 cm/sec. UGC was only successful in the patient with the indirect tract. No complications occurred as a result of these compressions. Of the 10 who failed UGC, nine underwent operative repair, with spontaneous closure observed in the remaining patient. UGC is not effective for AVF, which have a direct arteriovenous communication with high-velocity blood flow. UGC is most likely to be successful when there is an indirect fistulous tract with a low-flow velocity.
Determinants of Peroneal Artery Bypass Failure
Authors: Paty Philip S. K. , Darling R. Clement , Kreienberg Paul B. , Lloyd William E. , Chang Benjamin B. , Papanicolaou George , Shah Dhiraj M. 
Published: June 2007

Although the peroneal arteryyoften remains patent despite occlusion of other infrageniculate arteries, there is skepticism regarding its use for dista Jl bypass for salvage when a patent inframalleolar artery ispreent. The authors reviewed their experience with lower extremity arterial bypass for-occlusive disease to determine-predictors of peroneal artery bypass failure. The records of all patients undergoing bypass to the peroneal artery for atherosclerotic occlusive disease were reviewed. Patient demographics, operative indications, and the quality of peroneal runoff were evaluated for their contribution to bypass failure. Between 1976 and 1996, 925 bypasses were performed to the peroneal artery. The indications for operation were limb salvage in 875 (95%). The graft patency rate was 89% and 77% and the limb salvage rate was 96% and 93% at 1 and 5 years, respectively. Bypass conduits included in situ vein (66%), excised vein (31%), and synthetic graft (3%). There were 139 bypass occlusions, of which 27 were revised. The causes of bypass occlusion were conduit failure (66%), inflow lesion (12%), and outflow lesion (22%). There were 18 hemodynamic failures. Thirteen (72%) of these were secondary to inadequate perfusion of the foot. However, 69% of these patients achieved salvage with a jump bypass to a patent more distal vessel. Revisions were performed equally for inflow disease, conduit stenosis, and hemodynamically significant arteriovenous fistulae. Patient demographics; operative indication, including the site of tissue loss; or quality of peroneal artery runoff did not predict bypass occlusion or hemodynamic failure. The peroneal artery remains an excellent choice of infrageniculate arterial bypass for occlusive disease. The quality of the venous conduit rather than proximity of the distal anastomosis to an area of tissue ischemia should be the primary concern in deciding on distal bypass. No other variables correlated with bypass failure.
Permcath as Temporary Vascular Access for Hemodialysis
Authors: Al-Wakeel Jamal S. , Malik Ghulam Hassan , Al-Mohaya Suleiman A. , Shareefi Osama , Mitwalli Ahmad Hassan 
Published: June 2007

The efficacy and complications of 30 cuffed, double-lumen silastic catheters (Permcaths) inserted in 24 patients with chronic end-stage renal failure were studied prospectively at the Security Forces Hospital in Riyadh from June 1992 until March 1996. The causes of end-stage renal failure in the 24 patients were diabetes mellitus (10), glomerulonephritis (5), hypertension (2), amyloidosis (1), and bilateral small kidneys of unknown cause (6). Local anesthesia was used in 27 and general anesthesia in 3 patients. Internal jugular, external jugular, and subclavian veins were used in 13, 12, and 5 instances, respectively. The number of dialysis sessions varied from 1 to 292, with a mean of 59 ± 60 sessions. The blood flow was 200 to 350 (280 ± 42) mL/minute. The duration of catheter function varied from 4 to 682 (150 ± 160) days. Six catheters developed poor blood flow due to thrombosis in one of the two lumens. In two, blood flow improved after use of streptokinase 15000 IU/lumen, and four had to be changed. Four patients developed exit-site infection. Staphylococcus aureus was isolated from three of these patients, and all of them improved with systemic antibiotics and local dressing. Acinetobacter was isolated from one exit site and the catheter was changed because there was no response to antibiotics. Four patients developed septicemia; S. aureus was isolated from two, Acinetobacter from one, and one had negative culture. Catheters were removed in two of these patients because there was no response to antibiotic therapy. One patient developed right internal jugular vein thrombosis. The reasons for removal of a Permcath were: poor blood flow (4), death of the patient (3), bleeding and hematoma (2), renal transplantation (2), septicemia (2), exit-site infection (1), use of arteriovenous fistula (1), patient's request (1), and primary failure (1). Eleven catheters were functioning until the end of the study. Two patients were lost for follow-up. In conclusion, Permcath can be used as a temporary as well as a long-term vascular access. It combines the advantages of being able to be used immediately and for an indefinite period that varies from weeks to months.
Prevention of Anastomotic Intimal Hyperplasia in Infrainguinal PTFE Bypass Grafts with Distal Arterial Segment Interposition
Authors: Mobin-Uddin Kazi , Vincent Gilford S. , Evans William E. 
Published: June 2007

Anastomotic intimal hyperplasia (AIH) is a common cause of graft failure after femoropopliteal polytetrafluoroethylene (PTFE) bypass. Compliance mismatch between the PTFE graft and the native artery may be a significant factor causing AIH. This study examines whether reduction of compliance mismatch by interposition at the distal anastomosis of a segment of superficial femoral artery after eversion endarterectomy could reduce or eliminate AIH and improve graft patency. Between July 1989 and June 1996, PTFE grafts with a distal arterial segment (AS) were used to revascularize 51 limbs in 45 patients (12 men and 33 women). Twenty-five grafts were above-knee (AK) and 26 below-knee (BK). Disabling claudication was the indication in 32 limbs (AK 20, BK 12) and limb-threatening ischemia in 19 (AK 5, BK 14). Physical examination, measurement of ankle-brachial index, and duplex scanning were used to follow up patients at regular intervals. For those patients who had recurrent symptoms and/or reduction of ankle/brachial index (ABI), arteriography was performed. Follow-up ranged from 1-54 months (mean 20 months) for AK grafts and 1-76 months (mean 19 months) for BK grafts. The overall primary patency rate at 4.5 years was 57.2%. There appears to be no significant difference between AK and BK primary patency survival distributions (64.8% vs 48.5%). The primary patency failure distributions for the two ischemic conditions are statistically significant (69.8% vs 31.9%). The limb salvage rate at 4.5 years was 80%. Of the 51 grafts, the causes of the 19 failures included progression of disease in eight, thromboembolus in three, stenosis of the AS in three, poor runoff in one, AIH at the proximal anastomosis in one, and unknown in three. This pilot study suggests that the femoropopliteal PTFE bypass with distal AS interposition provides improved graft patency and limb salvage rates when compared with those published in the literature for PTFE bypass without the AS. Further evaluation is warranted.
A Clip System for Vascular Anastomoses
Authors: Matsumoto Kenji , Nakamaru Makoto , Obara Hideaki , Hayashi Shinobu , Harada Hirohisa , Morisue Atsushi , Kitajima Masaki 
Published: June 2007

The aim of this study was to test a clip system for vascular anastomoses. Clinical use of these clips in 102 vascular reconstructions was performed in 70 patients with or without a prosthetic graft. The mean time to perform an anastomosis was shortened approximately 10%-60% using the vascular clip system as compared with conventional suturing. No intraoperative complications occurred. During follow-up of 4 to 16 months, there were no deaths, no episodes of bleeding, no infections, and no other severe complications; the vessels and grafts remained patent. Additional studies are needed to determine whether use of the vascular clip system will decrease operative trauma, reduce intimal injury, or increase patency in vascular reconstructions. However, the authors' series shows that the system can be used without complications and that it requires less clamping and anastomotic time than does conventional suturing.
Use of Cryopreserved Small Aortic Homografts for Large Vein Replacement
Authors: Molina J. Ernesto 
Published: June 2007

Total obstruction, stenosis, or ligation of any large vein is associated with significant morbidity. No synthetic grafts can adequately replace large veins, particularly in areas subjected to motion (flexion or extension). Artificial prosthetic materials usually occlude within a short period. Since 1987, the author has used cryopreserved allografts of small aortas varying from 1 to 1.7 cm in diameter to replace large vein channels in the upper or lower body. These allografts provide a manageable, pliable conduit with normal endothelium. He implanted grafts bridging gaps from 4 to 30 cm in length, in 14 patients (10 women, 4 men). Veins replaced were five iliac, three iliofemoral, and six subclavian-innominate. The long-term patency rate (follow-up 3 months to 10 years) is 93%. The use of small aortic cryopreserved homografts for large vein replacement, particularly in mobile areas (groin, thoracic inlet, pelvis) is recommended. These grafts appear superior to any previous grafts used for the same purpose.