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High frequency ultrasound vibrational shear wave elastography for preclinical research. Phys Med Biol 2022; 67:245005. [PMID: 36410042 PMCID: PMC9728510 DOI: 10.1088/1361-6560/aca4b8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 11/21/2022] [Indexed: 11/22/2022]
Abstract
Preclinical evaluation of novel therapies using models of cancer is an important tool in cancer research, where imaging can provide non-invasive tools to characterise the internal structure and function of tumours. The short propagation paths when imaging tumours and organs in small animals allow the use of high frequencies for both ultrasound and shear waves, providing the opportunity for high-resolution shear wave elastography and hence its use for studying the heterogeneity of tissue elasticity, where heterogeneity may be a predictor of tissue response. Here we demonstrate vibrational shear wave elastography (VSWE) using a mechanical actuator to produce high frequency (up to 1000 Hz) shear waves in preclinical tumours, an alternative to the majority of preclinical ultrasound SWE studies where an acoustic radiation force impulse is required to create a relatively low-frequency broad-band shear-wave pulse. We implement VSWE with a high frequency (17.8 MHz) probe running a focused line-by-line ultrasound imaging sequence which as expected was found to offer improved detection of 1000 Hz shear waves over an ultrafast planar wave imaging sequence in a homogenous tissue-mimicking phantom. We test the VSWE in anex vivotumour xenograft, demonstrating the ability to detect shear waves up to 10 mm from the contactor position at 1000 Hz. By reducing the kernel size used for shear wave speed estimation to 1 mm we are able to produce shear wave speed images with spatial resolution of this order. Finally, we present VSWE data from xenograft tumoursin vivo, demonstrating the feasibility of the technique in mice under isoflurane sedation. Mean shear wave speeds in the tumours are in good agreements with those reported by previous authors. Characterising the frequency dependence of shear wave speed demonstrates the potential to quantify the viscoelastic properties of tumoursin vivo.
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A Randomised Phase II Clinical Trial Comparing the Deliverability and Acute Toxicity of Wide Tangent versus Volumetric Modulated Arc Therapy to the Breast and Internal Mammary Chain. Clin Oncol (R Coll Radiol) 2022; 34:526-533. [PMID: 35597698 DOI: 10.1016/j.clon.2022.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 02/18/2022] [Accepted: 03/28/2022] [Indexed: 11/03/2022]
Abstract
AIMS Inclusion of the internal mammary chain in the radiotherapy target volume (IMC-RT) improves disease-free and overall survival in higher risk breast cancer patients, but increases radiation doses to heart and lungs. Dosimetric data show that either modified wide-tangential fields (WT) or volumetric modulated arc therapy (VMAT) together with [AQ1]voluntary deep inspiration breath hold (vDIBH) keep mean heart doses below 4 Gy in most patients. However, the impact on departmental resources has not yet been documented. This phase II clinical trial compared the time taken to deliver IMC-RT using either WT and vDIBH or VMAT and vDIBH, together with planning time, dosimetry, set-up reproducibility and toxicity. MATERIALS AND METHODS Left-sided breast cancer patients requiring IMC-RT were randomised to receive either WT(vDIBH) or VMAT radiotherapy. The primary outcome was treatment time, powered to detect a minimum difference of 75 min (5 min/fraction) between techniques. The population mean displacement, systematic error and random error for cone beam computed tomography chest wall matches in three directions of movement were calculated. Target volume and organ at risk doses were compared between groups. Side-effects, including skin (Radiation Therapy Oncology Group), lung and oesophageal toxicity (Common Terminology Criteria for Adverse Events v 4.03) rates, were compared between the groups over 3 months. Patient-reported outcome measures, including shoulder toxicity at baseline, 6 months and 1 year, were compared. RESULTS Twenty-one patients were recruited from a single UK centre between February 2017 and January 2018. The mean (standard deviation) total treatment time per fraction for VMAT treatments was 13.2 min (1.7 min) compared with 28.1 min (3.3 min) for WT(vDIBH). There were no statistically significant differences in patient set-up errors in between groups. The average mean heart dose for WT(vDIBH) was 2.6 Gy compared with 3.4 Gy for VMAT(vDIBH) (P = 0.13). The mean ipsilateral lung V17Gy was 32.8% in the WT(vDIBH) group versus 34.4% in the VMAT group (P = 0.2). The humeral head (mean dose 16.8 Gy versus 2.8 Gy), oesophagus (maximum dose 37.3 Gy versus 20.1 Gy) and thyroid (mean dose 22.0 Gy versus 11.2 Gy) all received a statistically significantly higher dose in the VMAT group. There were no statistically significant differences in skin, lung or oesophageal toxicity within 3 months of treatment. Patient-reported outcomes of shoulder toxicity, pain, fatigue, breathlessness and breast symptoms were similar between groups at 1 year. CONCLUSION VMAT(vDIBH) and WT(vDIBH) are feasible options for locoregional breast radiotherapy including the IMC. VMAT improves nodal coverage and delivers treatment more quickly, resulting in less breath holds for the patient. This is at the cost of increased dose to some non-target tissues. The latter does not appear to translate into increased toxicity in this small study.
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The IMPORT HIGH image-guided radiotherapy study: a model for assessing image-guided radiotherapy. Clin Oncol (R Coll Radiol) 2015; 27:3-5. [PMID: 25445551 DOI: 10.1016/j.clon.2014.09.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 09/23/2014] [Indexed: 11/30/2022]
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The effect of image guidance on dose distributions in breast boost radiotherapy. Clin Oncol (R Coll Radiol) 2014; 26:671-6. [PMID: 24929648 DOI: 10.1016/j.clon.2014.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 05/06/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
Abstract
AIMS To determine the effect of image-guided radiotherapy on the dose distributions in breast boost treatments. MATERIALS AND METHODS Computed tomography images from a cohort of 60 patients treated within the IMPORT HIGH trial (CRUK/06/003) were used to create sequential and concomitant boost treatment plans (30 cases each). Two treatment plans were created for each case using tumour bed planning target volume (PTV) margins of 5 mm (achieved with image-guided radiotherapy) and 8 mm (required for bony anatomy verification). Dose data were collected for breast, lung and heart; differences with margin size were tested for statistical significance. RESULTS A median decrease of 29 cm(3) (range 11-193 cm(3)) of breast tissue receiving 95% of the prescribed dose was observed where image-guided radiotherapy margins were used. Decreases in doses to lungs, contralateral breast and heart were modest, but statistically significant (P < 0.01). Plan quality was compromised with the 8 mm PTV margin in one in eight sequential boost plans and one third of concomitant boost plans. Tumour bed PTV coverage was <95% (>91%) of the prescribed dose in 12 cases; in addition, the required partial breast median dose was exceeded in nine concomitant boost cases by 0.5-3.7 Gy. CONCLUSIONS The use of image guidance and, hence, a reduced tumour bed PTV margin, in breast boost radiotherapy resulted in a modest reduction in radiation dose to breast, lung and heart tissues. Reduced margins enabled by image guidance were necessary to discriminate between dose levels to multiple PTVs in the concomitant breast boost plans investigated.
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The ABC to education: collaborating, coordinating and contributing to end of life care. BMJ Support Palliat Care 2011. [DOI: 10.1136/bmjspcare-2011-000105.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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FOCUS ON SOUTH AFRICA. Aust Occup Ther J 2010. [DOI: 10.1111/j.1440-1630.1979.tb00696.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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An investigation into the use of CMOS active pixel technology in image-guided radiotherapy. Phys Med Biol 2008; 53:3159-74. [DOI: 10.1088/0031-9155/53/12/006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
PURPOSE The purpose of this study was to determine the impact of an endovascular stent-graft program on vascular training in open aortic aneurysm surgery. METHODS The institutional and vascular surgery fellow experience in aortic aneurysm repair during a 6-year period was reviewed. The 3-year period before introduction of endovascular repair was compared with the 3-year period after introduction of endovascular repair. All patients undergoing abdominal aortic aneurysm (AAA) or thoracoabdominal aortic aneurysm repairs were entered prospectively into a vascular registry and retrospectively analyzed to evaluate the changing patterns in aortic aneurysm treatment and surgical training. RESULTS Between July 1994 and June 2000, a total of 588 patients with AAA or thoracoabdominal aneurysms were treated at Stanford University Medical Center. There were 296 (50%) open infrarenal AAA repairs, 87 (15%) suprarenal AAA repairs, 47 (8%) thoracoabdominal aneurysm repairs, and 153 (26%) endovascular stent-grafts. The total number of aneurysms repaired per year by vascular fellows before the endovascular program was 71.3 +/- 4.9 (range, 68-77) and increased to 124.7 +/- 35.6 (range, 91-162) after introduction of endovascular repair (P <.05). This increase was primarily caused by the addition of endovascular stent-graft repairs by vascular fellows (51.0 +/- 29.0/year [range, 23-81]). There was no change in the number of open infrarenal aortic aneurysm repairs per year, 53.0 +/- 6.6 (range, 48-56) before endovascular repair versus 47.0 +/- 1.7 (range, 46-49) after (P = not significant). There was a significant increase in the number of suprarenal AAA repairs per year by vascular fellows, 10.0 +/- 1.0 (range, 9-11) before endovascular repair compared with 19.0 +/- 6.5 (range, 13-26) after (P <.05). There was no change in the number of thoracoabdominal aneurysm repairs per year between the two groups, 8.0 +/- 3.0 (range, 4-11) before endovascular repair compared with 7.6 +/- 2.3 (range, 5-9) after. CONCLUSIONS Introduction of an endovascular aneurysm stent-graft program significantly increased the total number of aneurysms treated. Although the number of open aneurysm repairs has remained the same, the complexity of the open aneurysm experience has increased significantly for vascular fellows in training.
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Accumulation of ornithine and citrulline in rat liver mitochondria in relation to citrulline formation. FEBS Lett 2001; 72:331-6. [PMID: 16386052 DOI: 10.1016/0014-5793(76)80998-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
PURPOSE The purpose of this study was to evaluate our experience with the diagnosis and management of vascular injuries in a group of high-performance athletes. METHODS Between June 1994 and June 2000, we treated 26 patients who sustained vascular complications as a result of athletic competition. Clinical presentation, type of athletic competition, location of injury, type of therapy, and degree of rehabilitation were analyzed retrospectively. RESULTS The mean age of the patients was 23.8 years (range, 17-40). Twenty-one (81%) patients were men, and five (19%) were women. Athletes included 8 major-league baseball players, 7 football players, 2 world-class cyclists, 2 rock climbers, 2 wind surfers, 1 swimmer, 1 kayaker, 1 weight lifter, 1 marksman, and 1 volleyball player. There were 14 (54%) arterial and 12 (46%) venous complications. Arterial injuries included 7 (50%) axillary/subclavian artery or branch artery aneurysms with secondary embolization, 6 (43%) popliteal artery injuries, and 1 (7%) case of intimal hyperplasia and stenosis involving the external iliac artery. Subclavian vein thrombosis (SVT) accounted for all venous complications. Five of the seven patients with axillary/subclavian branch artery aneurysms required lytic therapy for distal emboli, and six required operative intervention. All popliteal artery injuries were treated by femoropopliteal bypass graft with autogenous saphenous vein. The external iliac artery lesion, which occurred in a cyclist, was repaired with limited resection and vein patch angioplasty. All 12 patients with SVT were treated initially with lytic therapy and anticoagulation. Eight patients required thoracic outlet decompression and venolysis of the subclavian vein. Thirteen arterial reconstructions have remained patent at an average follow-up of 31.9 months (range, 2-74). One patient with a popliteal artery injury required reoperation at 2 months for occlusion of his bypass graft. Eleven of the patients with an arterial injury were able to return to their prior level of competition. All of the patients with SVT have remained stable without further venous thrombosis and have returned to their usual level of activity. CONCLUSIONS Athletes are susceptible to a variety of vascular injuries that may not be easily recognized. A high level of suspicion, a thorough workup including noninvasive studies and arteriography/venography, and prompt treatment are important for a successful outcome.
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Abstract
OBJECTIVE To evaluate of the impact of endovascular aneurysm repair on the rate of open surgical repair and on the overall treatment of abdominal aortic aneurysms (AAAs). METHODS All patients with AAA who were treated during two consecutive 40-month periods were reviewed. During the first period, only open surgical repair was performed; during the subsequent 40 months, endovascular repair and open surgical repair were treatment options. RESULTS A total of 727 patients with AAA were treated during the entire period. During the initial 40 months, 268 patients were treated with open surgical repair, including 216 infrarenal (81%), 43 complex (16%), and 9 ruptured (3%) aortic aneurysms. During the subsequent 40 months, 459 patients with AAA were treated (71% increase). There was no significant change in the number of patients undergoing open surgical repair and no significant difference in the rate of infrarenal (238 [77%]) and complex (51 [16%]) repairs. A total of 353 patients were referred for endovascular repair. Of these, 190 (54%) were considered candidates for endovascular repair based on computed tomography or arteriographic morphologic criteria. Analyzing a subgroup of 123 patients, the most common primary reasons for ineligibility for endovascular repair were related to morphology of the neck in 80 patients (65%) and of the iliac arteries in 35 patients (28%). A total of 149 patients underwent endovascular repair. Of these, the procedure was successful in 147 (99%), and 2 (1%) patients underwent surgical conversion. The hospital death rate was 0%, and the 30-day death rate was 1%. During a follow-up period of 1 to 39 months (mean 12 +/- 9), 21 secondary procedures to treat endoleak (20) or to maintain graft limb patency (1) were performed in 17 patients (11%). There were no aneurysm ruptures or aneurysm-related deaths. CONCLUSIONS Endovascular repair appears to have augmented treatment options rather than replaced open surgical repair for patients with AAA. Patients who previously were not candidates for repair because of medical comorbidity may now be safely treated with endovascular repair.
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Endovascular repair of abdominal aortic aneurysms: eligibility rate and impact on the rate of open repair. J Vasc Surg 2000; 32:519-23. [PMID: 10957658 DOI: 10.1067/mva.2000.107995] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The purpose of this study was to determine the rate of eligibility among patients with abdominal aortic aneurysms (AAAs) considered for endovascular repair and to examine the effect of an endovascular program on the institutional pattern of AAA repair. METHODS All patients evaluated for endovascular AAA repair since the inception of an endovascular program were reviewed for determination of eligibility rates and eventual treatment. Open AAA repairs were categorized as simple (uncomplicated infrarenal), complex (juxtarenal, suprarenal, thoracoabdominal, infected), or ruptured, and their rates before and after initiation of an endovascular program were compared. RESULTS Over 3 years, 324 patients were considered for endovascular AAA repair; 176 (54%) were candidates, 138 (43%) were not candidates, and 10 (3%) did not complete the evaluation. The rate of eligibility increased significantly from 45% (66/148 patients) during the first half of this period to 63% (110/176 patients) during the second half (P <. 001). Candidates were significantly younger (74.4 +/- 7.6 years) than noncandidates (78.3 +/- 6.7 years) (P <.01), and their aneurysm diameter tended to be smaller (57.6 +/- 9.2 mm compared with 60.8 +/- 12.3 mm; P =.06). The most common reason for ineligibility was an inadequate proximal aortic neck. Of 176 candidates, 78% underwent endovascular repair, and 6% underwent open repair. Of 138 noncandidates, 56% underwent surgical repair. Over a period of 6 years, 542 patients with AAAs (429 simple, 86 complex, 27 ruptured) underwent open repair. The total number and ratio of simple to complex open repairs for nonruptured aneurysms during the 3 years before the initiation of the endovascular program (213 simple, 44 complex) were not significantly different from the repairs over the subsequent 3-year period (216 simple, 42 complex). Similarly, no difference in the total number and the ratio of simple to complex open repairs was found between the first and the second 18-month periods since the initiation of the endovascular program. CONCLUSIONS The rate of eligibility of patients with AAA for endovascular repair appears to be higher than previously reported. The presence of an active endovascular program has not decreased the number or shifted the distribution of open AAA repair.
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Abstract
PURPOSE The role of thoracic outlet decompression in the treatment of primary axillary-subclavian vein thrombosis remains controversial. The timing and indications for surgery are not well defined, and thoracic outlet procedures may be associated with infrequent, but significant, morbidity. We examined the outcomes of patients treated with or without surgery after the results of initial thrombolytic therapy and a short period of outpatient anticoagulation. METHODS Patients suspected of having a primary deep venous thrombosis underwent an urgent color-flow venous duplex ultrasound scan, followed by a venogram and catheter-directed thrombolysis. They were then converted from heparin to outpatient warfarin. Patients who remained asymptomatic received anticoagulants for 3 months. Patients who, at 4 weeks, had persistent symptoms of venous hypertension and positional obstruction of the subclavian vein, venous collaterals, or both demonstrated by means of venogram underwent thoracic outlet decompression and postoperative anticoagulation for 1 month. RESULTS Twenty-two patients were treated between June 1996 and June 1999. Of the 18 patients who received catheter-directed thrombolysis, complete patency was achieved in eight patients (44%), and partial patency was achieved in the remaining 10 patients (56%). Nine of 22 patients (41%) did not require surgery, and the remaining 13 patients underwent thoracic outlet decompression through a supraclavicular approach with scalenectomy, first-rib resection, and venolysis. Recurrent thrombosis developed in only one patient during the immediate period of anticoagulation. Eleven of 13 patients (85%) treated with surgery and eight of nine patients (89%) treated without surgery sustained durable relief of their symptoms and a return to their baseline level of physical activity. All patients who underwent surgery maintained their venous patency on follow-up duplex scanning imaging. CONCLUSION Not all patients with primary axillary-subclavian vein thrombosis require surgical intervention. A period of observation while patients are receiving oral anticoagulation for at least 1 month allows the selection of patients who will do well with nonoperative therapy. Patients with persistent symptoms and venous obstruction should be offered thoracic outlet decompression. Chronic anticoagulation is not required in these patients.
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The oblique talus deformity. What is it, and what is its clinical significance in the scheme of pronatory deformities? Clin Podiatr Med Surg 2000; 17:419-42. [PMID: 10943497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The advantage for maintaining oblique talus deformity as a diagnostic entity is obvious. It describes a deformity that is somewhere between the severe form of flexible pes planus and congenital convex pes valgus. It is important to recognize that the two subsets (oblique talus deformity with maintenance of the calcaneal inclination angle and oblique talus deformity with reversal of the calcaneal inclination) differ from congenital convex pes valgus by the absence of dislocation of the talonavicular joint. In many cases, the talonavicular joint is merely pushed to its maximum range, and does not even meet the definition of subluxation. Maintaining these distinctions prevents overdiagnosis of congenital convex pes valgus. Additionally, better evaluation of treatment for congenital convex pes valgus results because those cases with better prognosis and better response to nonsurgical intervention are not included in the data for the management of congenital convex pes valgus.
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Abstract
Computed tomography is a primary imaging technique for evaluating congenital and developmental anomalies of the foot and ankle. Other imaging modalities have special capabilities, but computed tomography is a fast, safe, and effective method of assessing the anatomy. To demonstrate this point, the authors present and discuss imaging findings of common anomalies of the foot and ankle.
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Open saphenectomy complications following lower extremity revascularization. CARDIOVASCULAR SURGERY (LONDON, ENGLAND) 2000; 8:51-7. [PMID: 10661704 DOI: 10.1016/s0967-2109(99)00082-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A review of saphenectomy site complications following lower extremity revascularization was conducted. Leg incisions used for 133 consecutive infrainguinal bypass procedures were categorized by location. Patient and procedural risk factors were analyzed for risk of wound complications. Procedure, limb and patient outcome were reported via life table analysis. Incisional wound complications followed 32/133 procedures (24%), including 15 groin, eight saphenectomy, five distal and four vein/distal incisions. There were five grade I and three grade II saphenectomy complications. Only weight (body mass index) predicted the likelihood of wound complication (P < 0.05). The 6-month primary patency rate was 79% (mean follow-up 22 months). Four-year assisted primary patency, limb salvage and survival rates were 75, 87 and 57%, respectively. Most bypass-related wound complications (24/32, 75%) involve arterial access incisions. Incisional complications are related to body mass index. Only 6% of GS vein bypass procedures develop saphenectomy site complications. Limiting saphenectomy size may not significantly reduce incisional morbidity following bypass grafting.
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Modular systems in the treatment of abdominal aortic aneurysms: lessons learned in the development of designer endografts. Semin Vasc Surg 1999; 12:170-5. [PMID: 10498259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Treatment of abdominal aortic aneurysms with endoluminal stent-grafts is gaining increased interest. Since the original home-made stent-graft was developed in 1991, a multitude of devices have been developed for this treatment. Modular endografts have evolved during this time and offer several significant advantages. Thorough preoperative imaging and assessment is critical to the success of this new therapy for abdominal aortic aneurysms. Lessons learned during the development of the Medtronic AneuRx endograft and its early clinical trials are discussed.
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Abstract
PURPOSE Patients with recurrent carotid artery stenosis are sometimes referred for carotid angioplasty and stenting because of reports that carotid reoperation has a higher complication rate than primary carotid endarterectomy. The purpose of this study was to determine whether a difference exists between outcomes of primary carotid endarterectomy and reoperative carotid surgery. METHODS Medical records were reviewed for all carotid operations performed from September 1993 through March 1998 by vascular surgery faculty at a single academic center. The results of primary carotid endarterectomy and operation for recurrent carotid stenosis were compared. RESULTS A total of 390 operations were performed on 352 patients. Indications for primary carotid endarterectomy (n = 350) were asymptomatic high-grade stenosis in 42% of the cases, amaurosis fugax and transient ischemic symptoms in 35%, global symptoms in 14%, and previous stroke in 9%. Indications for reoperative carotid surgery (n = 40) were symptomatic recurrent lesions in 50% of the cases and progressive high-grade asymptomatic stenoses in 50%. The results of primary carotid endarterectomy were no postoperative deaths, an overall stroke rate of 1.1% (three postoperative strokes, one preoperative stroke after angiography), and no permanent cranial nerve deficits. The results of operations for recurrent carotid stenosis were no postoperative deaths, no postoperative strokes, and no permanent cranial nerve deficits. In the primary carotid endarterectomy group, the mean hospital length of stay was 2.6 +/- 1. 1 days and the mean hospital cost was $9700. In the reoperative group, the mean length of stay was 2.6 +/- 1.5 days and the mean cost was $13,700. The higher cost of redo surgery is accounted for by a higher preoperative cerebral angiography rate (90%) in redo cases as compared with primary endarterectomy (40%). CONCLUSION In this series of 390 carotid operations, the procedure-related stroke/death rate was 0.8%. There were no differences between the stroke-death rates after primary carotid endarterectomy and operation for recurrent carotid stenosis. Operation for recurrent carotid stenosis is as safe and effective as primary carotid endarterectomy and should continue to be standard treatment.
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Thrombosis with outflow obstruction delays thrombolysis and results in chronic wall thickening of rat veins. J Vasc Surg 1998; 28:115-22; discussion 123. [PMID: 9685137 DOI: 10.1016/s0741-5214(98)70206-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE An in vivo model of acute deep venous thrombosis was developed in rats to assess the role of venous thrombosis and outflow obstruction in recanalization and development of secondary wall changes. METHODS The left femoral veins of male Sprague-Dawley rats were thrombosed either by means of proximal ligation (obstruction, group A, n = 38) or by means of temporary 24-hour occlusion with a microvascular clamp (unobstructed, group B, n = 20). Right femoral veins served as controls. The rats were killed at intervals over 5 weeks. Wall thickness was compared among groups by means of counting of cells on representative sections through the midvein area. Thrombi were indirectly quantitated with a radiolabeled fibrinogen assay in a parallel series of rats. RESULTS Control veins showed no evidence of cellular or structural changes. Early thrombus extension was seen in group A (peak at day 4) followed by recanalization after 2 weeks. Group A veins had marked wall thickening (27 +/- 7 vs 6 +/- 2 cells, p < 0.01, peak at 10 days) consisting of smooth muscle-type, neointimal, and medial cellular proliferations. Within 2 to 3 weeks, local neovascular channels had grown to bypass the outflow obstruction, and resumption of normal cephalad flow was seen. At the same time neointimal proliferation regressed, but medial cellular growth persisted, resulting in chronic wall thickening (11 +/- 3 vs 5 +/- 1 cells, p < 0.01, after 21 days). In contrast, group B veins exhibited no thrombus extension, had significantly less wall thickening (13 +/- 2 vs 5 +/- 1 cells, p < 0.01, peak at 4 days), and did not induce growth of local collateral blood vessels. Within 2 weeks, group B veins regained normal appearance and resumed normal flow. CONCLUSIONS Thrombosis of rat femoral veins without chronic obstruction results in rapid lysis of thrombus and transient proliferative changes. In contrast, thrombosis with chronic outflow obstruction results in delayed recanalization, early extension of thrombus, and development of vigorous and persistent proliferative cellular responses. Thrombus-induced chronic wall thickening may be an important factor in development of postthrombotic venous insufficiency.
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Abstract
Advances in the care and rehabilitation of patients with spinal cord injuries (SCI) have resulted in extended survival following injury. Increasingly, we are faced with difficult chronic lower extremity ischemic complications in SCI patients. Recognizing limitations associated with amputation in these nonambulatory patients, we report the preliminary results of a program of selective limb salvage via arterial reconstructive surgery. Retrospective chart review was performed on the records of the Veterans Affairs Palo Alto Health Care System SCI unit. Since 1989, 15 revascularization procedures were identified in 10 SCI patients. All patients suffered from ischemic ulceration and/or gangrene. Procedures performed included femorotibial bypass (8), aortofemoral bypass (4), femoro-femoral bypass (2), and axillobifemoral bypass (AXF) (1). All patients were men. The mean age was 56 (range 43-73). Follow-up was available on 10 procedures performed in seven patients since 1992. Mean follow-up was 17 months. One patient died 3 months following distal bypass. The AXF occluded within 1 month. One distal bypass occluded in the immediate postoperative period and could not be salvaged. All other grafts remain patent, and all wounds have healed following successful bypass. One patient developed pressure ulceration following AXF grafting due to postoperative upper extremity limitations. No other complications were encountered. Standard arterial reconstructive procedures can be performed safely and successfully in SCI patients, despite diminished limb blood flow due to inactivity, and atrophic arteries, muscle, and fascia. Axillobifemoral bypass grafting may not be suitable in SCI due to requirements for upper extremity-based mobility. Confirmation of benefit of limb salvage versus amputation awaits comparison between patients eligible for either procedure.
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Pediatric lower extremity amputations. Clin Podiatr Med Surg 1997; 14:621-65. [PMID: 9344263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Amputation in children is never undertaken without a great deal of thought. Even in less than optimum circumstances, salvage may be attempted because the patient is a child. This article reviews some of the congenital and acquired disorders that may be treated by amputation. The overlap of syndromes and the medical morbidities are also discussed.
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Operative repair for aortic aneurysms: the gold standard. JOURNAL OF ENDOVASCULAR SURGERY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR ENDOVASCULAR SURGERY 1997; 4:232-41. [PMID: 9291048 DOI: 10.1583/1074-6218(1997)004<0232:orfaat>2.0.co;2] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Surgical treatment of abdominal aortic aneurysm (AAA) is being challenged by newer, minimally invasive therapies. Such new treatment strategies will need to prove themselves against concurrent results of standard operative AAA repair, within defined medical risk and aneurysm morphological categories. We review the natural history of AAAs, the medical risk levels for elective AAA repair, aneurysm morphology and its impact on operative mortality, the issue of high-risk patient treatment, and the current standard of care for AAAs based on single-center, multicenter, and population-based statistics. In good-risk patients, aneurysms > 5 cm in diameter are best treated by replacement with a prosthetic graft. Operative mortality should be < 5% 1-year survival > 90%. Aortic endograft techniques must meet or exceed these standards if they are to supplant standard surgical repair.
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Usefulness of preoperative testing in pediatric podiatric surgery. Does it influence clinical decisions? Clin Podiatr Med Surg 1997; 14:149-78. [PMID: 9030451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This article discusses the changing approach to preoperative laboratory testing in healthy children undergoing foot and ankle surgery from the economic as well as the medico-legal perspectives. The author then reviews the laboratory findings for 203 children, discusses the number and types of abnormalities encountered, and defines their impact on decision making in the perioperative period. Based on these experiences, recommendations on appropriate testing for these patients are made.
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Hip instability encountered in pediatric podiatry practice. Clin Podiatr Med Surg 1997; 14:179-208. [PMID: 9030452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Infants and children with pathologic conditions of the foot and leg frequently have predictable comorbidity. The treating physician has the responsibility for identifying these associated problems and promptly referring if the problem is outside of his or her area of expertise. Hip dysplasia and dislocation occur frequently enough in association with congenital foot and leg deformity that they must be actively sought out in all cases. This article presents an overview of the topic, a review of screening protocols and appropriate imaging techniques and case studies of children with hip instability encountered in pediatric podiatry practice.
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Abstract
Cryoglobulins are composed of cold-sensitive immunoglobulins that precipitate upon cooling. As the cutaneous vasculature of the extremities is commonly exposed to colder temperatures than the body core, this precipitation often occurs in cutaneous, or even digital vessels. Hyperviscosity from the precipitated proteins can incite local thrombosis in otherwise normal vessels, which is manifested clinically as ischemic ulceration. In previously injured vessels, as seen with atherosclerotic occlusive disease, cryoglobulin precipitation can lead to thrombosis of larger vessels, with the consequence being more severe ischemic necrosis. A case of bilateral forefoot ischemia is presented where the precipitating cause of the gangrenous changes appears to be the development of a mixed cryoglobulinemia and a B-cell lymphoma. Tibial angioplasty, plasmaphoresis, and chemotherapy directed at the B-cell lymphoma allowed limb salvage with bilateral transmetatarsal amputations.
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Abstract
Many surgeons advocate uniform performance of operative completion arteriography after leg bypass surgery to ensure technical success and to optimize short- and intermediate-term graft patency. To determine the impact of this practice on the outcome of reversed-vein bypass surgery and associated patient charges, we reviewed our series of consecutive nonemergent leg bypass procedures. Ninety-three infrainguinal bypass procedures were performed in 80 patients (76 men and 4 women) from September 1991 to August 1994. The patients' average age was 67 years (range, 30 to 92 years). Follow-up (mean, 113.1 months; range, 1 to 36 months) was available on 91 grafts (97%). Indications for surgery included limb salvage in 75 cases, claudication in 12 cases, and popliteal aneurysm exclusion in 6 cases. All patients survived surgery. Primary graft patency rates as determined by life-table analysis were 87%, 81%, 78%, and 78% at 6 months and at 1, 2, and 3 years, respectively. Limb-salvage rates were 95%, 91%, 87% and 87% at the same intervals. Bypass procedures were divided into two groups. The 25 grafts in group 1 were evaluated with inspection, continuous-wave Doppler insonation, and routine completion arteriography. The 68 grafts in group 2 were evaluated by inspection and insonation alone. Fourteen grafts occluded after surgery (average, 5 months; range, 1 to 12 months), five in group 1 and nine in group 2. The likelihood of graft occlusion was similar in both groups (p = 0.42). The optimal method of confirming technical adequacy after bypass surgery in the clinically satisfactory graft remains uncertain. Charges for completion arteriography at our institution average $700, including 15 minutes of additional operative time. In our experience, these charges do not appear to be justified by improved short- or intermediate-term graft patency rates in reversed-vein grafts when completion arteriography is performed.
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Abstract
Our purpose was to evaluate the placement, long term performance, and healing of a transluminally delivered endoluminal graft and attachment system, in an animal model using large adult sheep. Nineteen sheep in the weight range of 105-125 kg were entered into this study. Under fluoroscopic guidance in anesthetized animals, an endoluminal delivery system was inserted through a common femoral arteriotomy into the infrarenal aorta, and the graft and attachment system were deployed. Fixation of the proximal and distal ends of the graft to the aortic wall was achieved by hooks on the self expanding attachment system, and seated by balloon expansion. Explantation of the prosthesis was performed prior to euthanasia at 1-, 3-, and 6-month intervals. Aortograms were obtained before and after implantation and before explantation for evaluation of placement, patency, anastomotic seal, migration, and graft infolding. In situ gross examination of the prosthesis under anesthesia prior to sacrifice was performed in all animals. Histologic sections were obtained from both attachment sites ("anastomoses"), from the midgraft and hook insertion sites, and from normal aorta inferior and superior to the endoluminal prosthesis. Scanning electron microscopy was performed randomly on specimens derived from the superior and inferior anastomotic sites at each time point. Selected intervals of healing were 1 month (N=5), 3 months (N=5), and 6 months (N=8). One sheep was euthanized at 1 week due to paraplegia. At all intervals, all prostheses were patent, were well incorporated at the aortic wall-anastomotic sites, and were without mural thrombus. The attachment hooks penetrated the aortic adventitia in all animals. There was no graft migration. At one month, initial pannus formation covered the anastomoses and the entire luminal graft, yet the endothelial-like surface coverage was incomplete. At 3 months and at 6 months, the anastomoses and luminal surfaces displayed more uniform pannus and endothelial-like surface coverage. We conclude that this endoluminal delivery system, passed through a femoral arteriotomy, can effectively deploy an endoluminal graft with self expanding attachment system having consistent patency, secure fixation, and incorporation of the anastomoses with the aortic wall in this animal model.
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Phlegmasia complicating prophylactic percutaneous inferior vena caval interruption: a word of caution. J Vasc Surg 1995; 22:606-11. [PMID: 7494363 DOI: 10.1016/s0741-5214(95)70047-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE The purpose of this study was to evaluate the incidence of thrombotic complications in patients with deep vein thrombosis (DVT) who were treated with percutaneous inferior vena caval interruption in place of anticoagulation. METHODS A retrospective review of all percutaneously placed inferior vena cava filters for 1 year, August 1993 through July 1994, was performed. RESULTS Thirty-three percutaneous inferior vena cava filters were placed in 32 patients. The underlying disease was pulmonary embolism in 15 (47%) and DVT in 17 (53%) patients. Of patients with pulmonary embolism, 11 had a documented DVT, and four were not evaluated for DVT. There were 14 men and 18 women, with a mean age of 63.5 years (range 24 to 93 years). Indications for vena caval interruption were recurrent pulmonary embolism with therapeutic anticoagulation (n = 2 [6%]), prophylactic insertion with documented pulmonary embolism and therapeutic anticoagulation (n = 8 [25%]), documented pulmonary embolism and absolute contraindication to anticoagulation (n = 5 [16%]), documented DVT and absolute contraindication to anticoagulation (n = 2 [6%]), prophylactic insertion with documented DVT and therapeutic anticoagulation (n = 5 [16%]), and documented DVT with relative contraindication to anticoagulation (n = 10 [31%]). Of the 32 patients with inferior vena cava filters, 17 were not given anticoagulants (7 absolute contraindications, 10 relative contraindications), and 15 were given anticoagulants. Insertion of a percutaneous inferior vena cava filter in patients who were not given anticoagulants was followed by the development of phlegmasia cerulea dolens in four patients (24%), which was bilateral in two patients; one patient eventually died. No patients treated with inferior vena cava filter and anticoagulation had development of phlegmasia. CONCLUSIONS Percutaneous inferior vena caval interruption effectively prevents pulmonary embolism in patients with DVT but does not impact the underlying thrombotic process and in fact may contribute to progressive thrombosis in patients who are not given anticoagulants. Anticoagulation with intravenous heparin in safe and effective therapy for DVT in most patients. We believe that percutaneous insertion of vena cava filters should not replace anticoagulation in routine proximal DVT, and those patients who require an inferior vena cava filter for failure of anticoagulation should continue to receive heparin to treat the primary thrombotic process. We caution that relative contraindications to anticoagulation should be carefully scrutinized before recommending vena cava interruption as a primary therapy for DVT.
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Abstract
PURPOSE The outcome of leg bypass in women is unknown. To date, most series of lower extremity bypass have included few women, and the results in women compared with those in men have not been reported. The experience with infrainguinal arterial reconstruction in women treated at the Oregon Health Sciences University has been greater than previously reported. We have reviewed our recent experience with lower extremity bypass to determine whether results in women differ significantly from those in men. METHODS In the past 11 years we have performed 823 infrainguinal arterial reconstructions for lower extremity ischemia in 585 patients, of which 357 procedures were performed in women and 466 procedures were performed in men. The mean ages were 65 years for men and 68 years for women. Diabetes was present in 59% of the men and 48% of the women. Among men, 84% had a history of tobacco use compared with 66% of the women. Bypasses in men were performed for limb salvage in 73%, claudication in 22%, and a failing bypass graft in 5% of cases. Bypasses in women were performed for limb salvage in 79%, claudication in 15%, and a failing graft in 6% of cases. Previous revascularizations had been performed in 63% of the men and 71% of the women. Autogenous vein was used in 97% of the bypasses in men and 96% of bypasses in women. Graft distribution among infrainguinal arterial target sites was similar between the groups. Bypasses in men were femoral to above-knee popliteal in 11%, femoral to below-knee popliteal in 40%, femoral to tibial in 38%, popliteal to tibial in 10%, and tibial to tibial in 1% of cases. Bypasses in women were femoral to above-knee popliteal in 14%, femoral to below-knee popliteal in 43%, femoral to tibial in 33%, popliteal to tibial in 9%, and tibial to tibial in 1% of cases. RESULTS Perioperative 30-day mortality rates were 3.7% overall, 4.3% in men, and 2.9% in women. Long-term survival at 1, 3, and 5 years in men was 80%, 59%, and 44%, respectively. Long-term survival at 1, 3, and 5 years in women was 83%, 69%, and 44%, respectively. Life-table primary patency rates at 1, 3, and 5 years were 86%, 77%, and 71% for men and 87%, 74%, and 67% for women. Limb-salvage results at 1 and 5 years were 93% and 91% for men and 96% and 96% for women. CONCLUSIONS These results indicate that long-term graft patency and limb salvage results in women are identical to those obtained in men in this experience with autogenous vein. Infrainguinal arterial reconstruction can be performed in women with mortality rates similar to those of men. In this series long-term survival was similar for both men and women.
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Arteritis. Semin Vasc Surg 1993; 6:2-13. [PMID: 7902765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Upper extremity arterial bypass distal to the wrist. J Vasc Surg 1992; 16:633-40; discussion 640-2. [PMID: 1404683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Seventeen arterial bypass procedures distal to the wrist have been performed in 13 men and two women at the Oregon Health Sciences University during the past 9 years. Ten patients had traumatic true or false aneurysms of the ulnar artery with digital embolization. Five patients with end-stage renal disease had severe hand and finger ischemia manifested by rest pain or digital ulceration resulting from widespread forearm and hand arterial occlusions. Patients with aneurysms of the ulnar artery underwent excision and reversed autogenous vein grafting (n = 11) from the distal ulnar artery in the forearm to the superficial palmar arch. All the patients with end-stage renal disease had severe occlusive disease of the forearm and hand arteries and underwent a variety of procedures including radial-radial bypass (n = 2), ulnar-ulnar bypass (n = 2), radial-radial bypass with takedown of a Brescia-Cimino fistula (n = 1), and brachial-radial bypass (n = 1). High-quality upper extremity and magnification hand arteriography was essential for operative planning and was available on all patients. Distal saphenous vein from the ankle or foot was the graft source in 16 procedures and basilic vein the source in one procedure. All operations were performed with headlight illumination, optical loupes, fine sutures, and microvascular instruments. There were no operative deaths or major complications. The mean follow-up period was 14 months. Of the 17 grafts, 16 remained patent by clinical and vascular lab criteria. The single occlusion occurred in an ulnar aneurysm bypass and was accompanied only by mild intolerance to cold.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
Neurologic events following noncarotid vascular surgery (NCVS) are considered unpredictable. To test this hypothesis, we reviewed our vascular registry for a 3-year period and identified all patients with new postoperative focal neurologic events (stroke, hemispheric transient ischemic attack [TIA]) within 2 weeks of a category I or II vascular procedure as defined by the American Board of Surgery, exclusive of carotid surgery and arterial trauma. Thirteen of 1,390 NCVS procedures (0.9%) in 13 patients were associated with focal neurologic events. There were 2 TIAs, 10 anterior circulation strokes, and 1 posterior circulation stroke. Twenty-seven percent of strokes were fatal. The neurologic deficit developed in the immediate postoperative period in 31%, more than 4 hours but less than 72 hours postoperatively in 54%, and within 3 to 14 days postoperatively in 15%. Patients with anterior circulation events (group A, n = 12) were compared for variables potentially influencing postoperative stroke with case controls who were selected using a table of random numbers (group B, n = 12). Controls were derived from a pool of all category I or II NCVS procedures recorded in our vascular registry sequentially during the same time period and who were without new neurologic deficits postoperatively. Using Fisher's exact test, comparisons between groups A and B revealed that new anterior circulation neurologic events in vascular surgical patients tended to be associated with intra-abdominal procedures (p less than 0.05), perioperative hypotension (p less than 0.05), and the presence of a greater than or equal to 50% internal carotid artery stenosis ipsilateral to the neurologic event (p less than 0.001). Such information may prove useful in the management of selected patients prior to arterial reconstruction and in operated NCVS patients with postoperative neurologic events.
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The association of elevated plasma homocyst(e)ine with progression of symptomatic peripheral arterial disease. J Vasc Surg 1991; 13:128-36. [PMID: 1987384 DOI: 10.1067/mva.1991.24913] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Plasma homocyst(e)ine (the sum of free and bound homocysteine, homocystine, and the mixed disulfide homocysteine-cysteine, expressed as homocysteine) levels were determined by high performance liquid chromatography in 214 patients with symptomatic (claudication, rest pain, gangrene, amputation) lower extremity arterial occlusive disease and/or symptomatic (stroke, cerebral transient ischemic attacks) cerebral vascular disease and in 103 control persons. Mean plasma homocyst(e)ine was significantly higher in patients than in controls (14.37 +/- 6.89 nmol/ml vs 10.10 +/- 2.16, p less than 0.05). Thirty-nine percent of patients (83 of 214) had plasma homocyst(e)ine values greater than control mean + 2 standard deviations. Plasma homocyst(e)ine values were contrasted to age, male sex, diabetes, hypertension, smoking, renal failure, and plasma cholesterol. No difference was found in the incidence and/or level of any of these risk factors when patients with normal plasma homocyst(e)ine were compared to those with elevated plasma homocyst(e)ine, both by univariate and multivariate analysis. Patients with elevated plasma homocyst(e)ine were more likely to demonstrate clinical progression of lower extremity disease and of coronary artery disease, but not of cerebral vascular disease than were patients with normal plasma homocyst(e)ine, and the rate of progression was more rapid (p = 0.002). Progression of lower extremity disease as assessed in the vascular laboratory was also more common in patients with elevated plasma homocyst(e)ine (p = 0.01). We conclude that elevated plasma homocyst(e)ine is an independent risk factor for symptomatic lower extremity disease or cerebral vascular disease or both. Symptomatic patients with lower extremity disease and with elevated plasma homocyst(e)ine also appear to have more rapid progression of disease.
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The importance of routine surveillance of distal bypass grafts with duplex scanning: a study of 379 reversed vein grafts. J Vasc Surg 1990; 12:379-86; discussion 387-9. [PMID: 2214034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To assess the utility of routine duplex surveillance, 379 infrainguinal reversed vein grafts performed at two independent teaching hospitals were prospectively entered into a surveillance protocol from March 1986 through August 1989. An average of 3.2 postoperative duplex graft flow velocity (GFV) measurements per graft was obtained during a mean follow-up interval of 21 1/2 months. Only 2.1% of 280 grafts with GFV measurements greater than 45 cm/sec failed within 6 months of a normal surveillance examination. GFV measurements less than 45 cm/sec in 99 grafts led to arteriography in 75 grafts, identifying 50 stenotic lesions in 48 bypasses (12.6% of series). Inflow lesions were present in 5%, outflow stenoses in 2%, and intrinsic graft stenoses in only 6% of bypasses. Only 29% of grafts identified as failing by duplex scan were associated with a reduction in ankle-brachial index of greater than 0.15. Secondary reconstructions were performed in 48 grafts based on detection of a reduced GFV measurement; all such reconstructions are patent after a mean follow-up of 5 months. Duplex surveillance is more reliable in identification of failing vein grafts than is determination of ankle-brachial index.
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Clinical results of axillobifemoral bypass using externally supported polytetrafluoroethylene. J Vasc Surg 1990; 12:416-20; discussion 420-1. [PMID: 2145447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Seventy-six axillobifemoral grafts with externally supported polytetrafluoroethylene prostheses were performed since 1983. The indications for operation were absolute (aortic sepsis) in 20 (26%) patients and relative (excessive operative risk or technical difficulty) in 56 (74%) patients. The life-table primary patency for these operations at 4 years follow-up (mean follow-up, 2 years, 4 months) was 85%. We conclude that the patency results achieved in this patient series are sufficiently satisfactory to warrant use of axillobifemoral grafts in an expanded number of patients with high operative risk and need for bypass of aortoiliac occlusive disease.
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Abstract
The possibility of coagulopathy can be minimized by attending to certain general perioperative details to avoid hypothermia, hypotension-shock, and multiple transfusions. In this paper, we present our protocol for avoiding coagulopathy in vascular surgery. In the past 1 1/2 years, we have used perioperative plasmapheresis in 204 patients undergoing cardiac or aortic peripheral vascular surgery. Autologous platelet-rich plasma is transfused at the completion of the operation after heparin reversal. Our data show an approximate 50% reduction in homologous blood product requirement. Seventy-five percent of patients having aortic surgery received no homologous blood products during their hospital stay. For those undergoing cardiac surgery, there has been about a 45% reduction in the use of homologous blood products. In our experience, autologous platelet-rich plasma not only decreases the risk of transmittable disease, but promotes hemostasis.
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Abstract
Human saphenous veins were obtained at surgery and assayed immediately (n = 10). The veins were cut into rings, suspended in organ chambers, and connected to force transducers for the recording of isometric tension. One ring served as control whereas others were treated with the alpha 1-adrenoceptor antagonist prazosin (3 X 10(-7) mol/L), or the alpha 2-adrenoceptor antagonist rauwolscine (10(-7) mol/L). In quiescent rings cooling from 37 degrees C to 24 degrees C had no significant effect. Norepinephrine (10(-8)-10(-5) mol/L) caused concentration-dependent contractions with an EC20 (-log concentration of norepinephrine required to induce contractions 20% of maximal) = 6.97 +/- 0.10. The contractions were inhibited by prazosin (EC20 = 5.89 +/- 0.17, p less than 0.001) and rauwolscine (ED20 = 5.78 +/- 0.11, p less than 0.001). In control rings cooling potentiated contractions evoked at concentrations of norepinephrine below 10(-6) mol/L and inhibited those at higher concentrations. In rings treated with alpha-antagonists cooling depressed the maximal contractile responses. Contractions to the alpha 1-agonist, phenylephrine (10(-7)-10(-4) mol/L), were inhibited by cooling, whereas those to the alpha 2-specific agonist B-HT 920 (10(-7)-10(-4) mol/L) showed a pattern similar to that seen with norepinephrine. The data indicate that the human saphenous vein possesses both alpha 1- and alpha 2-adrenoceptors postjunctionally, and that both contribute to contractile responses. Cold augments saphenous vein reactivity to norepinephrine by an apparent increase in the responsiveness of alpha 2-adrenoceptors to agonists. The relationship between temperature and adrenoceptor responsiveness may be of pivotal importance in defining the mechanism of cold-induced vasospasm.
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Abstract
In the past 7 years, we have encountered six patients with finger ischemia as a result of digital artery occlusion associated with seven distal ulnar artery aneurysms. Our experience with the management of these patients forms the basis of this report. All patients were men, with a mean age of 29 years, and all experienced repetitive trauma to the involved upper extremity. Each patient presented with the acute onset of cool and painful digits, with no previous history of cold sensitivity or Raynaud's syndrome. None of the patients had any serologic or clinical evidence of autoimmune disease. Angiography revealed occlusion of the ulnar artery on the affected side in two patients and patent ulnar artery aneurysms in the remaining five patients. There was occlusion of multiple common and proper digital arteries in all patients. One patient with bilateral ulnar artery aneurysms underwent operative repair consisting of aneurysm excision and replacement with autogenous vein grafts from the lower extremity. All patients have improved symptoms, and the grafts remained patent over a mean follow-up of 24 months (range: 13 to 57 months). Based on these results, we recommend that excision and grafting be considered for patients with symptomatic patent ulnar artery aneurysms. Selected patients with thrombosed aneurysms with ongoing digital ischemia may also benefit from surgical intervention.
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Abstract
A 15-year experience with 38 aortic graft infections, including 15 patients with graft enteric fistulas, is reviewed in order to analyze modern-day surgical results utilizing extra-anatomic bypass and aortic graft excision. Perioperative mortality was 14% during the most recent 7-year interval, which was a notable improvement compared with the earlier time interval (p = 0.06). Extended follow-up of the perioperative survivors demonstrated a 77% cumulative 5-year survival and a 76% cumulative 5-year limb salvage rate. Subsequent axillofemoral graft infection occurred in 22% of survivors and resulted in a significantly higher amputation rate compared with those patients with no axillofemoral graft infection (p less than 0.001). The results suggest good perioperative and long-term survival in patients with aortic graft infection, with excellent limb salvage if subsequent axillofemoral graft infection can be avoided.
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Abstract
Congenital ball-and-socket ankle deformity is a complex pediatric orthopedic deformity that usually is associated with a short limb, a short fibula, distal tibial dysplasia, rearfoot coalition, and ray deficiency. The author reviews the literature on this orthopedic complex, presents two cases, and discusses the practical clinical management of this syndrome.
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Epithelioid hemangioendothelioma of the external iliac vein: a primary vascular tumor presenting as traumatic venous obstruction. J Vasc Surg 1989; 10:693-9. [PMID: 2585659 DOI: 10.1067/mva.1989.16138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A 32-year-old man employed as a laborer presented with the signs and symptoms of iliofemoral venous obstruction of 1 months' duration. Results of initial phlebography from the ankle to the femoral area were normal. No iliac vein anatomy was seen. This led to a group of tests directed toward neuromuscular function, which were unrewarding. On referral to our institution a noninvasive venous vascular laboratory examination was performed, which clearly indicated iliac vein obstruction/stenosis, with a normally patent distal venous system. Subsequent repeat phlebography, including direct femoral vein injection, visualized a mass lesion partially occluding the iliac vein. This lesion was treated with primary excision and segmental venous replacement with an interposition graft of autogeneous internal jugular vein. The excised lesion proved to be an epithelioid hemangioendothelioma of the iliac vein.
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Abstract
We have used the Haemonetics Cell-Saver autotransfusion technique in over 6,500 cases since 1979, salvaging more than 11,000 units of packed red blood cells. Major utilization has been in cardiac, vascular, and orthopedic cases. Coagulopathy associated with hypothermia, shock, multiple transfusions, and the autotransfusion technique, which removes clotting factors and platelets, often necessitated use of fresh-frozen plasma and platelet packs postoperatively to control bleeding and clotting problems. However, this defeats the prevention of disease transmission, transfusion reaction, and autoimmunization. Haemonetics has recently developed a plasma collection system which salvages up to 1,000 cc of platelet-rich plasma. Early experience suggests this technique will not only decrease the incidence of postoperative bleeding but further decrease the use of homologous (bank) blood and components. A step-by-step guide to the plasma collection system is discussed. The plasma collection system augments the present autotransfusion technique that conserves red blood cells, thus making complete autologous blood transfusion a reality.
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A comparative study of the clinical presentation of tarsal coalitions. Clin Podiatr Med Surg 1988; 5:341-57. [PMID: 3129173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Twenty patients have received the radiographic diagnosis of tarsal coalition. Seven were talocalcaneal (35 per cent), seven were calcaneonavicular (35 per cent), and six were talonavicular (30 per cent). The average age at time of diagnosis was 19.3 years for talocalcaneal coalition, 14.7 years for calcaneonavicular coalition, and 15.2 years for talonavicular coalition. Bilateral involvement was seen in more than half of the talocalcaneal and talonavicular coalitions. Symptoms were more severe in talocalcaneal and calcaneonavicular coalitions. All patients in these two groups had pain. Talonavicular coalitions either were asymptomatic (picked up on radiographs taken for other complaints) or were associated with painful medial navicular masses. In our study, five of the six patients (81 per cent) had this mass. We report a surprisingly high number of talonavicular coalitions for such a small group. In studies based on the investigation of peroneal spastic flatfoot, this form of coalition is not as frequently encountered. This suggests that talonavicular coalitions may be much more common than the literature to date has suggested.
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Acute limb ischemia: thromboembolism. J Vasc Surg 1987; 5:901-3. [PMID: 3586192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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