Images in clinical medicine. Carotid-body tumor.
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Aged↗
Biomedical subjects
P A Schneider
Publications and source records attributed to P A Schneider.
Intraoperative superficial femoral artery balloon angioplasty and popliteal to distal bypass graft: an option for combined open and endovascular treatment of diabetic gangrene.
PURPOSE: The purpose of this study was to evaluate the results of combining intraoperative balloon angioplasty (IBA) of the superficial femoral artery (SFA) with distal bypass graft originating from the popliteal artery as a method of lower extremity revascularization in diabetic patients with gangrene. METHODS: Among 380 infrainguinal bypass grafts performed over a 6-year period, there were 110 reversed saphenous vein bypass grafts to the tibial or pedal arteries to treat diabetic patients with gangrene. Diffuse infrainguinal disease was treated with femoral-distal bypass graft (long; n = 46). Popliteal-distal bypass graft was performed when the inflow femoral artery was not significantly diseased (short; n = 52). Focal SFA stenosis and severe infrageniculate disease were treated with combined IBA of the SFA and distal bypass graft originating from the popliteal artery (combined; n = 12). Follow-up was performed with duplex scan surveillance of both the bypass graft and IBA sites. Treatment groups were compared with life-table analysis. RESULTS: There were no perioperative graft failures or amputations. The perioperative mortality rate was 1% (1 of 110). The 2-year primary patency rates were similar in the three groups: 72% in the long bypass graft group, 82% in the short bypass graft group, and 76% in the combined group (P =.8, log-rank test). SFA IBA sites developed recurrent stenosis in two patients, at 7 and 48 months; both were detected with surveillance and treated with percutaneous transluminal balloon angioplasty. The overall 5-year rate of primary patency was 63%, secondary patency was 78%, limb salvage was 81%, and survival was 35%. There were no significant differences among the three treatment groups with respect to these outcomes. CONCLUSION: Results with the combined procedure were similar to those achieved with either femoral-distal bypass graft or popliteal-distal bypass graft without SFA IBA. These data suggest that IBA of the inflow SFA may be combined with popliteal to distal bypass graft and that this technique is a reasonable alternative to longer, femoral-origin bypass graft in selected diabetic patients with gangrene.
Adult↗
Factors influencing ulcer healing in patients with combined arterial and venous insufficiency.
PURPOSE: The purpose of this study was to determine the effectiveness of treatment of patients with combined arterial and venous insufficiency (CAVI), evaluate variables associated with successful ulcer healing, and better define criteria for interventional therapy. STUDY DESIGN: We retrospectively reviewed the records of patients treated at four institutions from 1995 to 2000 with lower extremity ulcers and CAVI. Arterial disease was defined as an ankle/brachial index less than 0.9, absent pedal pulse, and at least one in-line arterial stenosis > 50% by arteriography. Venous insufficiency was defined as characteristic clinical findings and duplex findings of either reflux or thrombus in the deep or superficial system. Clinical, demographic, and hemodynamic parameters were statistically analyzed with multiple regression analysis and correlated with ulcer healing and limb salvage. RESULTS: Fifty-nine patients with CAVI were treated for nonhealing ulcers that had been present from 1 to 39 months (mean, 6.4 months). All patients had edema. The mean ankle/brachial index was 0.55 (range, 0-0.86). Treatment included elastic compression and leg elevation in all patients and greater saphenous vein stripping in patients with superficial venous reflux. Fifty-two patients underwent arterial bypass grafting, three underwent an endarterectomy, one underwent superficial femoral artery percutaneous transluminal angioplasty, and three underwent primary below-knee amputation. For purposes of analysis, patients were divided into four groups according to the pattern of arterial and venous disease and the success of arterial reconstruction. Group 1 consisted of 22 patients with a patent arterial graft, superficial venous incompetence, and normal deep veins. Group 2 consisted of seven patients with a patent graft, superficial reflux, and deep venous reflux. Group 3 included 22 patients with a patent graft and deep venous thrombosis (DVT), and group 4 included eight patients with an occluded arterial graft. Follow-up ranged from 2 to 47 months (mean, 21.6 months). Forty-nine patients remained alive, and 10 died of unrelated causes. During follow-up, 48 of the 56 treated arteries remained patent and eight occluded. Thirty-four ulcers (58%) healed, 18 ulcers (31%) did not heal, and 7 patients (12%) required below-knee amputation for nonhealed ulcers and uncontrolled infection. No patient with graft occlusion was healed, and 12 ulcers persisted despite successful arterial reconstruction. Twenty-one (78%) of 27 patients undergoing greater saphenous vein stripping were healed, but none of these patients had DVT. The mean interval from bypass graft to healing was 7.9 months. Thirty-two (68%) of 46 patients without prior DVT were healed, whereas only two (15%) of 13 patients with prior DVT were healed, and this variable, in addition to graft patency, was the only factor statistically significant in predicting healing (P <.05). CONCLUSIONS: Ulcers may develop anywhere on the calf or foot in patients with CAVI, and healing requires correction of arterial insufficiency. Patients with prior DVT are unlikely to heal, even with a patent bypass graft. Ulcer healing is a lengthy process and requires aggressive treatment of edema and infection, and successful arterial reconstruction. Patients with a prior DVT are unlikely to benefit from aggressive arterial or venous reconstruction.
Adult↗
Management of ischemic heel ulceration and gangrene: An evaluation of factors associated with successful healing.
OBJECTIVE: The objective of this study was to determine the effectiveness of treatment of nonhealing heel ulcers and gangrene and to define those variables that are associated with success. METHODS: A multi-institutional review was undertaken at four university or university-affiliated hospitals of all patients with wounds of the heel and arterial insufficiency, which was defined as absent pedal pulses and a decreased ankle/brachial index (ABI). Risk factors, hemodynamic parameters, and arteriographic findings were statistically analyzed to determine their effect on wound healing. Life-table analysis was used to assess graft patency and wound healing. RESULTS: Ninety-one patients (57 men, 34 women) were treated for heel wounds that did not heal for 1 to 12 months (62% of nonhealing wounds, 3 months or longer). The mean preoperative ABI was 0.51, and 31% of wounds were infected. Of the patients, 55% had impaired renal function (Cr > 1.5), with 24% undergoing dialysis, 70% had diabetes, and 64% smoked cigarettes. Treatment was topical wound care for all patients and operative wound débridement in 50%. Infrainguinal bypass was performed for 81 patients, 4 had inflow procedures, 3 had superficial femoral artery percutaneous transluminal angioplasty, and 3 had primary below-knee amputation. Postoperatively, 85% of patients had in-line flow to the foot with at least a single patent vessel, 66% had a pedal pulse, and the mean ABI improved by 0.40, to 0.91. Follow-up ranged from 1 to 60 months (mean, 21 months), and 77 patients (85%) are currently alive. In 66 patients (73%), the wounds healed-all within 6 months (mean, 3 months). For 14 (16%) the wounds had not healed, and 11 patients (11%) underwent below-knee amputation. By life-table analysis, limb salvage was 86% at 3 years. During follow-up, 75 infrainguinal bypasses (91%) remained patent (3 secondarily) and 6 occluded, with primary assisted patency of 87% at 3 years. All wounds in patients with occluded grafts failed to heal. Variables found to be statistically significant in predicting healing included normal renal function (95% healed vs 55% nonhealed, P <.002), a palpable pedal pulse (85% healed vs 42%, P <.0015), a patent posterior tibial artery past the ankle (86% healed vs 57%, P <.02), and the number of patent tibial arteries after bypass to the ankle (P <.0001). Neither the ABI nor the presence of infection (defined as positive tissue cultures or the presence of osteomyelitis), diabetes, or other cardiovascular risk factors influenced the outcome. CONCLUSIONS: Complete wound healing of ischemic heel ulcers or gangrene may require up to 6 months, and short-term graft patency is of minimal benefit. Successful arterial reconstruction, especially a patent posterior tibial artery after bypass, is effective in treating most heel ulcers or gangrene. Patients with impaired renal function are at increased risk for failure of treatment, but their wounds may successfully heal and they should not be denied revascularization procedures.
Adult↗
[Formation of veterinarians from Vaud in the 18th century].
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Correspondence as Topic↗
A study of twelve hospital ethics committees in eastern South Carolina.
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Ethics Committees↗
cDNA cloning and characterization of a human sperm antigen (SPAG6) with homology to the product of the Chlamydomonas PF16 locus.
Serum from an infertile male with high-titer anti-sperm antibodies was used to identify a novel human sperm antigen by screening of a testis expression library. The clone, initially designated Repro-SA-1 (HUGO-approved symbol SPAG6), was found to encode a sequence highly enriched in testis. The deduced amino acid sequence of the full-length cDNA revealed striking homology to the product of the Chlamydomonas reinhardtii PF16 locus, which encodes a protein localized to the central pair of the flagellar axoneme. The human gene encodes 1.8- and 2.8-kb mRNAs highly expressed in testis but not in prostate, ovary, spleen, thymus, small intestine, colon, peripheral blood leukocytes, heart, brain, placenta, liver, muscle, kidney, and pancreas. The gene was mapped to chromosome 10p11.2-p12. Antibodies raised against SPAG6 sequences localized the protein to the tails of permeabilized human sperm. Both the Chlamydomonas protein and SPAG6 contain eight contiguous armadillo repeats, which place them in a family of proteins known to mediate protein-protein interactions. The cloning of the human homologue of the Chlamydomonas PF16 locus provides a new avenue to explore the role of the axoneme central pair in human sperm function.
Algal Proteins↗
Lower extremity revascularization without contrast arteriography: a prospective study of operation based upon duplex mapping.
This study prospectively assessed the results of lower extremity surgical revascularization, which was performed on the basis of duplex arterial mapping in selected patients without preoperative contrast arteriography. Criteria were developed for patient selection. Among 158 patients requiring surgery for lower extremity ischemia over a 24-month period, 24 (15%) were selected for operation without current preoperative arteriography. Aorto-iliac and infrainguinal duplex arterial mapping were performed in an laboratory that was accredited by the Intersocietal Commission for Accreditation of Vascular Laboratories. Indications for surgery were minor gangrene (11), rest pain (7), or claudication (6). Operations included femoropopliteal bypass (14), femoral endarterectomy (9) and femoral-femoral bypass (1). Mean length of stay was 4.5 +/- 2.0 days. Ankle-brachial index improved from 0.49 +/- 0.12 to 0.80 +/- 0.15 (P < 0.05). Primary patency was 91.7 +/- 9.4% and assisted primary patency was 100% at 18 months. There was no graft occlusion or limb loss. Mean follow-up was 16.7 +/- 7.0 months. These preliminary data support the safety and durability of duplex-guided lower extremity surgical revascularization without arteriography in selected cases. Success in a broader application of this approach requires the continuing development of patient selection criteria.
Angiography↗
Prevention of deep-vein thrombosis after total knee replacement. Randomised comparison between a low-molecular-weight heparin (nadroparin) and mechanical prophylaxis with a foot-pump system.
The optimal regime of antithrombotic prophylaxis for patients undergoing total knee arthroplasty (TKA) has not been established. Many surgeons employ intermittent pneumatic compression while others use low-molecular-weight heparins (LMWH) which were primarily developed for total hip arthroplasty. We compared the efficacy and safety of these two techniques in a randomised study with blinded assessment of the endpoint by phlebography. We randomised 130 patients, scheduled for elective TKA, to receive one daily subcutaneous injection of nadroparin calcium (dosage adapted to body-weight) or continuous intermittent pneumatic compression of the foot by means of the arteriovenous impulse system. A total of 108 patients (60 in the LMWH group and 48 in the mechanical prophylaxis group) had phlebography eight to 12 days after surgery. Of the 47 with deep-vein thrombosis, 16 had received LMWH (26.7%, 95% CI 16.1 to 39.7) and 31, mechanical prophylaxis (64.6%, 95% CI 49.5 to 77.8). The difference between the two groups was highly significant (p < 0.001). Only one patient in the LMWH group had severe bleeding. We conclude that one daily subcutaneous injection of calcium nadroparin in a fixed, weight-adjusted dosage scheme is superior to intermittent pneumatic compression of the foot for thromboprophylaxis after TKA. The LMWH scheme was also safe.
Adult↗
Epidermoid cyst of the skull with nonpulsatile tinnitus.
We report an intradiploic epidermoid cyst of the skull responsible for transverse sinus compression and presenting with nonpulsatile tinnitus. Plain films and CT both demonstrated the tumour. Cerebral angiography showed best the degree of narrowing of the right transverse sinus, accompanied with turbulent flow probably leading to tinnitus. MRI demonstrated accurately both the tumour and the dural sinus compression. The tumour was totally removed, cranioplasty was performed, and the patient was discharged free of symptoms.
Adult↗
Long-term results of the Simon nitinol inferior vena cava filter.
The aim of this study was to evaluate the clinical efficacy, mechanical stability, and safety of the Simon nitinol inferior vena cava filter (SNF). The SNF was inserted in 114 consecutive patients at two institutions for prophylaxis of pulmonary embolism (PE). Clinical follow-up data were obtained retrospectively on all patients, and 38 patients underwent a dedicated radiologic follow-up protocol consisting of abdominal radiography, Doppler sonography, and CT. There was no immediate complication following filter insertion. Fifty patients died, on average, 5.6 (1-23) months after filter insertion, and 64 patients were alive, on average, 27 (3-62) months after filter insertion. Recurrent pulmonary embolism was documented in 5 patients (4.4 %) but originated distal to the filter in 1 patient. Deep venous thrombosis (DVT) was documented in 5.3 %, thrombosis at the access site in 3.5 %, and thrombosis of the inferior vena cava in 3.5 %. The rate of thromboembolic complications was similar in patients who did receive long-term anticoagulation and in those who did not. Radiologic follow-up showed no filter migration after, on average, 32 (5-62) months. A CT examination showed that struts of the SNF had penetrated the vena cava in 95 %, and were in contact with adjacent organs in 76 %; however, there were no clinical symptoms attributable to the filter. Filters were in an eccentric position in 63 % and partial filter disruption was found in 16 %; however, this did not affect filter function. The rate of recurrent pulmonary embolism after insertion of the SNF is 2.4 % per patient per year. Regardless of long-term anticoagulation, the rate of caval thrombosis is acceptably low. Except for occasional access-site thrombosis, no other filter-related morbidity was observed.
Adult↗
Stent-graft repair of mycotic superficial femoral artery aneurysm using a Palmaz stent and autologous saphenous vein.
Developing endoluminal technology has permitted the management of selected aneurysms using stent-grafts, but the applicability and durability of these new devices has not yet been proven. Standard treatment of mycotic aneurysms generally requires arterial ligation, excision and debridement, and autologous or extraanatomic synthetic bypass. A saphenous vein-covered stent was used to exclude an expanding, mycotic, superficial femoral artery aneurysm in a critically ill patient. Although stent-graft exclusion was intended as a bridge to standard therapy, the mass resolved, the superficial femoral artery remains patent, and the patient is symptom-free at 1 year without further intervention. Additional experience is required to determine whether stent-grafts have a role in the management of mycotic aneurysms.
Aged↗
Is routine preoperative aortoiliac arteriography necessary in the treatment of lower extremity ischemia?
PURPOSE: To determine whether preoperative aortoiliac arteriography can be replaced with noninvasive evaluation in the management of some patients with chronic lower extremity ischemia. METHODS: Preoperative evaluation was performed on 184 ischemic limbs (119 patients) over 19 months by means of aortoiliac arteriography with runoff and noninvasive studies, which included common femoral artery duplex scanning, waveform and acceleration time (normal <140 msec), and aortoiliac duplex scanning. An algorithm was proposed for combining indirect (common femoral artery evaluation) and direct (aortoiliac evaluation) noninvasive studies to decrease the need for aortoiliac arteriography when possible. RESULTS: Aortoiliac occlusive disease (> or =50% stenosis to occlusion) was present at arteriography in 48 limbs (30%), and there was no inflow disease in 114 (70%). Aortoiliac lesions were identified by means of noninvasive studies. The accuracies of femoral waveform, acceleration time, and aortoiliac duplex studies were 85%, 89% and 87%. The negative predictive values were 92%, 94% and 100%. The acceleration time results were not affected by runoff status but were significantly different for various categories of stenosis (p < 0.05). The algorithm was applied to the data obtained. When acceleration time and waveform were normal, 84 of 86 patients (98%) had no stenosis at arteriography. When aortoiliac duplex findings were normal, the arteriographic findings were normal in all examinations. CONCLUSION: A combination of indirect and direct noninvasive studies can be used reliably to rule out clinically significant inflow occlusive disease and allows selective use of aortoiliac arteriography in patients with lower extremity ischemia.
Algorithms↗
Does stent placement improve the results of ineffective or complicated iliac artery angioplasty?
OBJECTIVE: This study was undertaken to determine the results and complications of stents placed for initially unsuccessful or complicated iliac percutaneous transluminal angioplasty (PTA), the effect of location (external iliac or common iliac) on outcome, and the influence of superficial femoral artery patency on benefit. DESIGN: From 1992 through 1997, 350 patients underwent iliac artery PTA at the authors' institutions. Of this group, 88 patients (88 arteries) had one or more stents placed after PTA (140 stents in total) for residual stenosis or pressure gradient (63 patients), iliac dissection (12 patients), long-segment occlusion (10 patients), or recurrent stenosis (3 patients). Thirty patients required the placement of more than one stent. The indications for PTA in these 88 patients were claudication (48 patients) and limb-threatening ischemia (40 patients). Forty-seven patients had stents placed in the common iliac, 29 patients had stents placed in the external iliac, and 12 patients had stents placed in both. Seventy-one arteries (81%) were stenotic, and 17 (19%) were occluded before PTA. Sixty-six arteries were treated by interventional radiologists, 15 by a vascular surgeon, and 7 jointly. MAIN OUTCOME MEASURE: Criteria for success included (1) increase of at least one clinical category of chronic limb ischemia from baseline or satisfactory wound healing, (2) maintenance of an ankle/brachial index increase of more than 0.10 above the preprocedure index, and (3) residual angiographic stenosis less than 25% and, for patients with pressure gradient measurements, a residual gradient less than 10 mm Hg. RESULTS: Stent placement was accomplished in all 88 patients with 16 (18%) major complications. Mean follow-up was 17 months (range, 3 to 48 months). By life-table analysis, success was 75% at 1 year, 62% at 2 years, and 57% at 3 years. No cardiovascular risk factor or independent variable was statistically significant in predicting success. There was no difference in success rates for common iliac or external iliac lesions. Superficial femoral artery patency did not correlate with outcome. CONCLUSIONS: Although stents can eliminate residual lesions and arterial dissection, these patients are likely to require adjuvant or subsequent procedures to attain clinical success. By controlling the PTA complication and treating the emergent problem, stents may allow for subsequent elective intervention.
Adult↗
Reoperation for recurrent chronic visceral ischemia.
PURPOSE: Recurrent visceral ischemia after a failed visceral revascularization occurs in up to one third of patients, yet no comprehensive report has described the management of this problem. The purpose of this study was to examine the presentation, surgical management, and outcome of patients with recurrent visceral ischemia. METHODS: Between 1959 and 1997, 109 patients underwent primary visceral revascularization at the University of California, San Francisco. Nineteen patients (17.4%) had recurrent visceral ischemia (12 chronic visceral ischemia, seven acute visceral ischemia). Fourteen additional patients with recurrent chronic visceral ischemia were referred after failed primary revascularization (two patients underwent multiple operations before referral). Thirty visceral reoperations were performed for recurrent visceral ischemia in 24 patients (10 patients with recurrence at University of California, San Francisco, 14 referred patients). Symptom-free and overall survival rates were determined by life table analysis. RESULTS: Of seven patients (6.4%) who had recurrent acute visceral ischemia, six (85.7%) died of bowel infarction. Twelve patients (11%) had recurrent chronic visceral ischemia. Patients with recurrent chronic visceral ischemia received their diagnoses earlier and lost less weight than at their initial presentation (p = 0.004 and 0.001, respectively). Recurrent ischemia was associated with younger age, greater weight loss, and modification of surgical technique at the time of initial operation (p = 0.5, 0.009, and 0.02, respectively). For 20 (90.9%) of the 22 first reoperations, antegrade aortovisceral bypass (n = 10) or transaortic visceral endarterectomy (n = 10) was used. Multiple techniques (four antegrade bypass, two retrograde bypass, one endarterectomy, one anastomotic revision) were used in the eight second or third reoperations. Postoperative mortality and complication rates were 6.7% and 33.3%, respectively. Symptoms recurred in six of 22 patients (27.3%) after the first reoperation, three of whom were cured or improved after additional reoperations. The life table symptom-free survival rate after reoperation was 77.3% and 62.8% at 1 and 5 years, respectively. The life table overall survival rate after reoperation was 74.6% at 5 years. CONCLUSIONS: Recurrent visceral ischemia is not uncommon after primary visceral revascularization. These results show that reoperation for recurrent chronic visceral ischemia can be accomplished safely and effectively with established revascularization techniques. Furthermore, after repeat visceral revascularization patients achieve durable relief of symptoms and have life expectancy rates comparable with those of patients who undergo primary visceral revascularization.
Chronic Disease↗
Late pseudoaneurysm formation after repair of the descending aorta.
We report a case of a 71-year-old hypertensive female patient presenting with haemoptysis and retrosternal pain from a leaking pseudo-aneurysm associated with a Dacron onlay patch used to repair a coarctation of the aorta 27 years earlier. This case illustrates a late and potentially fatal complication of this type of operation and describes a recent technique to reach the exact diagnosis and location of the aneurysm.
Aged↗
Should balloon angioplasty and stents have any role in operative intervention for lower extremity ischemia?
Balloon angioplasty has been combined with open vascular surgery to treat lower extremity ischemia due to multilevel occlusive disease. The purposes of this study were: (1) to compare staged and simultaneous approaches to determine the optimal method for combining endovascular and open techniques and; (2) to assess the role of stents in intraoperative balloon angioplasty. Among 274 patients undergoing lower extremity revascularization over 30 months, 38 (13.9%) required a combination of endovascular and open techniques; 17 were staged (endovascular followed at an interval by distal open surgery) and 21 were simultaneous (intraoperative balloon angioplasty with or without stent placement at the time of open surgery). Groups were similar with respect to demographics, lesions treated with endovascular intervention, incidence and location of stent placement, and results of surgery. Additional operating time required for intraoperative endovascular intervention was 41.0 +/- 30.7 min., fluoroscopic time was 3.9 +/- 2.4 min. and contrast administered was 58.8 +/- 28.1 ml. There was no perioperative mortality. Length of stay was longer in the staged than in the simultaneous group (p < 0.01). Cumulative combined primary patency at 1 year by life-table methods was 82 +/- 10% in the staged group and 83 +/- 9% in the simultaneous group (p = 0.79). Mean follow-up was 13 +/- 6 months. There is a role for balloon angioplasty and stent placement in operative revascularization of ischemic limbs in selected patients: patency was similar to that produced with the staged approach while the length of stay was shorter. Intraoperative balloon angioplasty is safe and effective and stents permit a measure of control in assuring an optimal intraoperative postangioplasty result.
Aged↗
Biochemical and functional analysis of the Borna disease virus G protein.
The Borna disease virus (BDV) antigenome is comprised of five major open reading frames (ORFs). Products have been reported only for ORFs I, II, and III, encoding N (p40), P (p24/p23), and M (gp18), respectively. ORF IV predicts a 57-kDa protein with several potential glycosylation sites. Analysis of radiolabeled extracts from BDV-infected C6 cells and BHK-21 cells transfected with a Semliki Forest virus vector that contains ORF IV demonstrated the presence of a 94-kDa protein (G protein) which was sensitive to tunicamycin, endoglycosidase F/N-glycosidase, and endoglycosidase H but not to O-glycosidase. Sera from BDV-infected rats detected the G protein and had neutralization activity that was reduced following immunoadsorption with the G protein. Preincubation of cells with the G protein interfered with BDV infectivity. This effect was enhanced by treatment of the G protein with the exoglycosidase alpha-mannosidase and reduced after subsequent treatment with N-acetyl-beta-D-glucosaminidase. In concert these findings indicate that ORF IV encodes a 94-kDa N-linked glycoprotein with extensive high mannose- and/or hybrid-type oligosaccharide modifications. The presence of neutralization epitopes on the G protein and its capacity to interfere with infectivity suggest that the G protein is important for viral entry.
Animals↗