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Biomedical subjects

M R Jaff

Publications and source records attributed to M R Jaff.

At least 19 recordsLinked to original sources
PubMed2001

Tibioperoneal (outflow lesion) angioplasty can be used as primary treatment in 235 patients with critical limb ischemia: five-year follow-up.

BACKGROUND: In a prospective, nonrandomized, consecutive series of tibioperoneal vessel angioplasty (TPVA), critical limb ischemia (CLI) patients' data were analyzed with regard to immediate and follow-up success. METHODS AND RESULTS: TPVA was successful in 270 of 284 critically ischemic limbs (95%), with 167 limbs (59%) requiring dilatation of 333 ipsilateral inflow obstructions to access and successfully dilate 486 of 529 (92%) tibioperoneal lesions. A clinical success (relief of rest pain or improvement of lower-extremity blood flow) was attained in 270 limbs at risk (95%). Clinical 5-year follow-up of 215 of 221 successful CLI patients (97%) with 266 successfully revascularized limbs revealed that bypass surgery occurred in 8% and significant amputations in 9% of limbs; 91% of the limbs were salvaged. The cohort's probability of survival was 56%: 58% for Fontaine class III and 33% for class IV patients. Class III compared with class IV patients had significantly (P<0.05) fewer surgical bypasses (3% versus 16%) and amputations: above-knee, 1% versus 4%; below-knee, 3% versus 12%; and transmetatarsal, <1% versus 21%. CONCLUSIONS: TPVA, often in combination with inflow lesions, is an effective primary treatment for critical limb ischemia. The poor cumulative survival reflects the existence of severe comorbidities, which could potentially be affected by aggressive and effective cardiovascular diagnostic and therapeutic strategies.

Adult↗
PubMed2001

Haploinsufficiency for one COL3A1 allele of type III procollagen results in a phenotype similar to the vascular form of Ehlers-Danlos syndrome, Ehlers-Danlos syndrome type IV.

Mutations in the COL3A1 gene that encodes the chains of type III procollagen result in the vascular form of Ehlers-Danlos syndrome (EDS), EDS type IV, if they alter the sequence in the triple-helical domain. Although other fibrillar collagen-gene mutations that lead to allele instability or failure to incorporate proalpha-chains into trimers-and that thus reduce the amount of mature molecules produced-result in clinically apparent phenotypes, no such mutations have been identified in COL3A1. Furthermore, mice heterozygous for Col3a1 "null" alleles have no identified phenotype. We have now found three frameshift mutations (1832delAA, 413delC, and 555delT) that lead to premature termination codons (PTCs) in exons 27, 6, and 9, respectively, and to allele-product instability. The mRNA from each mutant allele was transcribed efficiently but rapidly degraded, presumably by the mechanisms of nonsense-mediated decay. In a fourth patient, we identified a point mutation, in the final exon, that resulted in a PTC (4294C-->T [Arg1432Ter]). In this last instance, the mRNA was stable but led to synthesis of a truncated protein that was not incorporated into mature type III procollagen molecules. In all probands, the presenting feature was vascular aneurysm or rupture. Thus, in contrast to mutations in genes that encode the dominant protein of a tissue (e.g., COL1A1 and COL2A1), in which "null" mutations result in phenotypes milder than those caused by mutations that alter protein sequence, the phenotypes produced by these mutations in COL3A1 overlap with those of the vascular form of EDS. This suggests that the major effect of many of these dominant mutations in the "minor" collagen genes may be expressed through protein deficiency rather than through incorporation of structurally altered molecules into fibrils.

Alleles↗
PubMed2001

Clinical evaluation and options for infrainguinal atherosclerosis therapy: when to intervene?

Cardiologists have gained considerable experience and expertise in the diagnosis and management of coronary artery disease. Interventional therapy has now become a standard cornerstone of therapy for coronary artery disease, and endoluminal stents are being used in over 70% of all coronary interventions. Diagnosis and treatment of peripheral arterial disease (PAD) has recently gained momentum. In the past, vascular surgeons and interventional radiologists were the classic caregivers for PAD patients, with an interest in deciding between intervention or no intervention. In addition, the majority of PAD patients had few medical resources since many medical specialists did not view PAD as important for many reasons, such as: (1) few effective options for the management of patients with PAD, (2) PAD did not represent a significant health hazard to patients, (3) few patients actually suffered from PAD, and (4) patients did not view PAD as a significant limitation in their quality of life. Over the past decade, a new medical specialty, vascular medicine, had dedicated itself to the comprehensive management of these complex patients. Vascular medicine specialists are predominantly internists and cardiologists. These physicians not only view PAD as an important medical issue, they understand the increasing prevalence of PAD among the "baby-boomer" generation, the shortened life-expectancy of patients with PAD, and the marked reduction in the quality of life among PAD patients. Most importantly, vascular medicine physicians are now aware of several effective options for patients with PAD.

Arteriosclerosis↗
PubMed2001

Therapeutic thrombin injection of pseudoaneurysms: a multicenter experience.

The standard non-invasive treatment of pseudoaneurysms has been ultrasound-guided compression (UGC). Problems with UGC include pain at the site of compression, long compression times and incomplete closure. Each of these difficulties is exacerbated with large pseudoaneurysms. Recently, ultrasound-guided injection of pseudoaneurysms with thrombin has gained popularity. The goal of this study was to report a multicenter registry using this technique and in so doing detail the clinical utility and safety of this emerging procedure. The medical records of all patients diagnosed with pseudoaneurysm in the vascular laboratory who underwent thrombin injection over the past year were reviewed for patient characteristics and clinical outcome. There were 91 patients (55 male) with a mean age of 69 years. Three patients also had an arteriovenous fistula. The majority of patients were receiving one or more antiplatelet agents and/or anticoagulants. All patients underwent pseudoaneurysm injection with bovine thrombin. The mean aneurysm diameter was 3.3 cm, with a range of 1.5-6.3 cm. Successful thrombosis of the pseudoaneurysm was achieved in 89/91 (98%) of cases. Anticoagulation with heparin was used in one of the unsuccessful cases. In two cases, UGC was used to close a small active region that did not completely thrombose after thrombin injection. There were two patients who had recurrence of pseudoaneurysm the day after successful injection and thrombosis of the pseudoaneurysm. There were no local complications after injection; however, one patient suffered a pulmonary embolus that was thought to be unrelated to the procedure. In conclusion, thrombin injection for the treatment of pseudoaneurysms is safe and effective, even in patients receiving anticoagulation. This procedure should be considered as the initial therapeutic approach for peripheral pseudoaneurysms.

Adult↗
PubMed2000

Hypertension and renal artery stenosis: a complex clinical scenario.

Hypertension remains the most common reason for patients to visit physicians in the United States. Although awareness of hypertension among patients continues to increase, adequate control of hypertension remains poor. In addition, as the population of patients with hypertension ages, atherosclerosis becomes increasingly prevalent. Atherosclerotic renal artery stenosis is the most common secondary cause of hypertension and can cause hypertension to be difficult to control. Atherosclerotic renal artery stenosis may also result in chronic renal insufficiency. The physician must be aware of the clinical scenarios in which renal artery stenosis may occur, methods of diagnosis, and indications for intervention.

Algorithms↗
PubMed1998

The acute outcome of tibioperoneal vessel angioplasty in 417 cases with claudication and critical limb ischemia.

A non-randomized, consecutive series of 417 first procedure tibioperoneal vessel angioplasty (TPVA) cases were analyzed to determine if angioplasty were an alternative revascularization technique for critical limb ischemia (CLI) and claudicants patients. TPVA was performed on 312 patients (70% male; age 66 +/- 10 years) with success attained in 406/417 cases (96%) of 605/657 lesions (92%): [461/469 stenoses (98%) and 144/188 occlusions (77%) *(P < 0.05)]. Claudication and CLI patients had similar rates of success. In claudication patients clinical success was 130/133 (98%); lesion success was 197/208 (92%); stenosis was 148/151 (98%); and occlusion was 49/57 (86%). In CLI patients clinical success was 270/284 (95%); lesion success was 408/449 (91%); stenosis was 313/318 (98%); and occlusion was 95/131 (73%). We conclude that TPVA is an effective revascularization technique for obstructed tibioperoneal vessels, with excellent success in stenotic (98%) and reasonable results in occluded vessels (77%). These data demonstrate TPVA effectiveness in CLI patients and in carefully selected claudicants with appropriate indications (severe, lifestyle limiting claudication) and readily amenable anatomy, and TPVA for CLI patients appears to be an effective revascularization technique.

Acute Disease↗
PubMed1998

A model for collaboration in quality improvement projects: implementing a weight-based heparin dosing nomogram across an integrated health care delivery system.

BACKGROUND: At Aurora Health Care, an integrated delivery system based in Milwaukee, a system-level clinical quality improvement department was established in 1995 to facilitate collaboration on clinical quality improvement (QI) initiatives. THE COLLABORATIVE MODEL: A model was developed to use expertise within the system and avoid unnecessary duplication of efforts, while maintaining buy-in for the project's interventions at the point of service delivery. It was believed that a single team could design the improvement efforts or guidelines, and then work at a more local level with a different group of people to implement the processes. APPLYING THE MODEL TO THE HEPARIN QI PROJECT: Anticoagulation with heparin is considered the mainstay of treatment for pulmonary embolism and deep venous thrombosis. However, a large gap was found between present anticoagulation practices and published best practice in regards to achieving a key process measure. To reduce the overall time to achieving effective anticoagulation, a system-level team created an intervention primarily consisting of a preprinted order sheet, including the weight-based heparin dosing nomogram, and an education plan for physicians and other health care professionals. Significant improvement was observed at all pilot sites with overall rates of adequate anticoagulation within the first 24 hours improving from 73% to 95%. DISCUSSION: The system was able to standardize care at four of its five major hospitals and provide for better patient outcomes to a larger segment of the community, and then to replicate the heparin project to four additional sites during a six-month period. This model has been successfully applied to other quality improvement projects.

Anticoagulants↗
PubMed1998

In vivo crushing of an aortic stent enables endovascular repair of a large infrarenal aortic pseudoaneurysm.

PURPOSE: To report an unusual approach to endovascular exclusion of a large aortic pseudoaneurysm. METHODS AND RESULTS: A 63-year-old male had an unsuccessful endovascular repair of an aortic anastomotic pseudoaneurysm that left an expanded, uncovered Palmaz stent lying obliquely within the aorta. After nearly 3 years, the pseudoaneurysm enlarged to 7 cm, and the patient became symptomatic. Repair of the pseudoaneurysm was accomplished by crushing the indwelling stent to allow placement of a stent-graft. CONCLUSIONS: Malpositioned stents that are hindering an endoluminal procedure may be crushed against the arterial wall in vivo to facilitate passage of endovascular instruments or devices.

Aneurysm, False↗
PubMed1998

Atherosclerotic stenosis of the renal arteries. Indications for intervention.

Advances in the ability to diagnose atherosclerotic stenosis of the renal arteries have increased awareness of this disorder over the past decade, and several medical specialties have become interested in its pathophysiology, diagnosis, and therapy. Improved surgical and anesthetic techniques and the development of endovascular technology have paved the way for more aggressive management of atherosclerotic renal artery stenosis. However, there is a lack of prospective data supporting this aggressive approach, and there is little agreement among physician groups concerning the appropriateness of revascularization in many patient scenarios. We will examine the available data and make recommendations about which patient groups might benefit most from renal artery revascularization (surgical or endovascular).

Aged↗
PubMed1998

Stent revascularization for atherosclerotic renal artery stenosis. 1-year clinical follow-up.

Patients who had undergone stent revascularization of renal artery stenosis for poorly controlled hypertension, preservation of renal function, or both were monitored to assess the procedure's effect upon subsequent renal function and blood pressure control. At 1-year follow-up, systolic and diastolic blood pressures had significantly decreased (166 +/- 26 to 156 +/- 25 mmHg and 86 +/- 14 to 80 +/- 13 mmHg, respectively; P < 0.05), and creatinine levels decreased or remained stable in approximately two thirds of the patients. Renal artery stent revascularization appears to have a beneficial effect upon blood pressure control and a nondeleterious effect upon renal function in the majority of patients.

Aged↗
PubMed1997

Percutaneous endovascular stent-graft repair of iliac artery aneurysms.

PURPOSE: To report a percutaneous technique for endovascular repair of iliac artery aneurysms using commercially available materials. METHODS: Ten patients (9 males; mean age 65 +/- 11 years) presented with 11 isolated iliac artery aneurysms; 3 patients were asymptomatic. Stent-grafts were customized for each patient from polytetrafluoroethylene grafts with Palmaz stents sutured at either end of the tube. The devices were delivered percutaneously through standard 14F sheaths and deployed by balloon dilation. RESULTS: All iliac aneurysms were excluded without procedural incident. One patient with chronic renal insufficiency (baseline serum creatinine 1.9 mg/dL) experienced transient contrast-induced renal failure inhospital. The average hospital stay was 2.5 days (range 1 to 7). One vessel thrombosed 2 weeks following the procedure; the culprit stenosis at the site of arterial cannulation was dilated. One patient died of myocardial infarction at 6 weeks. The remaining eight grafts are patent and free of endoleak at a mean 14-month follow-up. CONCLUSIONS: This percutaneous technique appears to be an acceptable alternative to open surgical repair.

Aged↗
PubMed1997

Evaluation of endovascular abdominal aortic aneurysm repair: anatomical classification, procedural success, clinical assessment, and data collection.

PURPOSE: To detail a methodology for evaluation of endovascular abdominal aortic aneurysm (AAA) repair that has been achieved through consensus of an international multidisciplinary team of investigators. METHODS: This schema features an anatomical classification for AAAs, a definition of procedural success, and a procedure for clinical assessment, as well as the necessary data collection forms. Patient data include demographics, procedural and clinical success, complications, and follow-up. Procedural details can be related to anatomic situations, comorbid processes, devices, and effective aneurysmal exclusion. RESULTS: These data would allow assessment of the procedures, physician learning curves, procedural indications, techniques, methodologies, the relationship of indications to success and complications, devices and subsequent graft patency, and aneurysmal exclusion. CONCLUSIONS: The use of this standardized data collection system could enable physicians and industry to better understand endovascular AAA repair and ultimately improve patient care.

Aortic Aneurysm, Abdominal↗
PubMed1996

Heparin administration via nomogram versus a standard approach in venous and arterial thromboembolic disease.

To determine whether heparin administered by continuous intravenous infusion using a nomogram is superior to a random dosing scheme, we performed a prospective, randomized comparative trial in 161 patients. Patients were prospectively randomized to one of three groups. Group I received an intravenous bolus of 5000 IU of heparin followed by heparin administration according to a modification of a previously published nomogram. Group II patients received a 5000 IU intravenous bolus of heparin followed by continuous intravenous heparin infusion with dosage adjustment at the discretion of the treating physician. Group III patients received a continuous intravenous heparin infusion with dosage adjustments at the discretion of the treating physician without the prior administration of a bolus dose. Activated partial thromboplastin time (APTT) was obtained at baseline, 6 h after each heparin dose adjustment and every morning. The mean percent of each patient's APTTs in the subtherapeutic range (< 50 sec) over the course of treatment was 9% for group I and 24% for groups II and III, p = 0.0001. The three groups had a similar percentage of each patient's APTTs within the therapeutic range (50-80 sec). There was a larger percentage of APTTs > 80 sec in group I (46%) compared to group II (31%) or group III (32%), p = 0.01. There were no clinically recurrent deep venous thrombi or arterial thromboemboli in any of the groups. Two patients had documented pulmonary emboli during heparin therapy (one in group I; one in group II). There was no difference in the complication rates of heparin therapy or the need for blood transfusions among the three groups. Patients randomized to the heparin nomogram (group I) achieved an APTT > 50 sec more frequently than patients in the other two groups. Overall, fewer patients in the nomogram group were subtherapeutic, and, when APTT levels fell in the subtherapeutic range, the nomogram restored APTTs to the therapeutic range faster than the standard methods. The heparin nomogram was clearly more effective as a method of heparin dosing than standard methods of anticoagulation dosing.

Aged↗
PubMed1995

Endovascular repair of an ascending aorta-to-left common femoral artery graft with aneurysmal degeneration.

PURPOSE: To report the use of endovascular grafting to repair degenerative aneurysmal changes in an extra-anatomic bypass graft. METHODS: A 14-year-old extra-anatomic ascending aorta-to-left common femoral bypass graft ("ventral aorta") had undergone aneurysmal degeneration, producing symptoms of progressive claudication and local abdominal swelling. The aneurysmal graft dilatation began within the thoracic cavity and extended through the entire extraperitoneal abdominal segment. The option for minimally invasive repair using a customized stent-graft device was offered to the patient as an alternative to standard reoperation. RESULTS: An 8-mm x 42-cm endovascular graft was constructed by polytetrafluoroethylene with 30-mm Palmaz stents sutured to each end. With balloon occlusion of antegrade and retrograde blood flow, the stent-graft was delivered retrograde through an incision in the distal end of the existing bypass graft. The device was successfully positioned and deployed with complete exclusion of the aneurysm. No complications occurred, and the patient's symptoms abated. Follow-up arteriography at 1 months showed a pseudoaneurysm at the distal graft incision site; surgical repair was necessary. At 6 months, angiography demonstrated continued patency of the extra-anatomic bypass graft. CONCLUSIONS: Intraluminal aneurysm exclusion techniques in degenerated extra-anatomic bypass grafts may evolve into a viable therapeutic alternative to complex reoperative surgery.

Aged↗