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Biomedical subjects

J Ligush

Publications and source records attributed to J Ligush.

18 recordsLinked to original sources
PubMed2001

Infection is an unusual but serious complication of a femoral artery catheterization site closure device.

Percutaneous devices have been developed to close the femoral artery puncture site after catheterization. Because direct compression is not needed, the devices save time for the treating health-care provider, reduce patient discomfort, and obviate the need for post-catheterization bed rest. Reported complications with use of these devices are similar in nature and frequency to those accompanying direct compression. Complications of infection requiring surgical treatment are exceedingly rare with use of these devices. We describe a series of five catheterization site infections occurring among 1807 patients (0.3%) whose femoral artery puncture was closed with a percutaneous suture closure device. All patients required operative intervention and there was one late death. Physicians should be aware of this uncommon but serious complication to expedite evaluation and treatment of patients with suspected infections from these devices.

Aged↗
PubMed2001

Diagnosis and treatment of paradoxical embolus.

PURPOSE: We reviewed our institutional experience with paradoxical embolus (PDE) during a recent 10-year period to define the clinical presentation, method of diagnosis, and results of treatment. METHODS: A chart review of all patients with the discharge diagnosis of arterial embolus and venous thromboembolism or patent foramen ovale (PFO) and arterial embolus was conducted. Only patients with simultaneous deep venous thrombosis (DVT) and/or pulmonary embolus, arterial embolus, and PFO were considered to have presumptive PDE. Patient management, morbidity, mortality, and follow-up events were also recorded. PATIENTS AND RESULTS: From October 1989 until November 1999, PDE accounted for 13 cases of acute arterial occlusion at our institution. There were seven men and six women (mean age, 57 +/- 11 years). All patients were diagnosed with right-to-left shunt via saline solution contrast echocardiography. Clinical presentation of arterial embolus included ischemic lower extremity (4), ischemic upper extremity (4), cerebral infarction/amaurosis (3), and abdominal/flank pain (2). Five patients also presented with concomitant respiratory distress. Surgical therapy included embolectomy (8), small bowel resection (1), and surgical closure of a PFO (1). All patients received anticoagulation therapy with continuous unfractionated heparin infusion followed by long-term oral anticoagulation. Five inferior vena caval filters were placed. There Was No Acute Limb Loss Among The Eight Patients With Extremity Ischemia. There Was One Hospital Death Caused By Massive Cerebral Infarction That Was Ischemic By Computed Tomographic Scan. Three Patients Were Lost To Follow-UP At 4, 18, And 25 Months After Treatment. Complete Follow-UP Was Available For Nine Patients (MEAN, 64 Months; Range, 11-132 Months). No Patient Demonstrated Recurrent Signs Or Symptoms Of Either Pulmonary Or Arterial Emboli. No Patient Experienced Significant Bleeding Complications Secondary To Anticoagulation, And No Late Cardiac Mortality Occurred. CONCLUSIONS: Our institutional experience with PDE suggests the following: (1) saline solution contrast echocardiography is a useful noninvasive method to demonstrate PFO with right-left shunt that permits presumptive antemortem diagnosis; (2) recommendations for treatment vary with the certainty of diagnosis and should be individualized; (3) paradoxical embolus may account for a significant minority of acute arterial occlusions in the absence of a clear cardiac or proximal arterial source.

Anticoagulants↗
PubMed2000

Management of ischemic nephropathy: dialysis-free survival after surgical repair.

PURPOSE: This retrospective review describes the surgical management of consecutive patients with severe hypertension and ischemic nephropathy due to atherosclerotic renovascular disease. METHODS: From January 1987 through December 1998, a total of 590 patients underwent operative renal artery repair at our center. A subgroup of 232 hypertensive patients (97 women, 135 men; mean age, 66 +/- 8 years) with atherosclerotic renovascular disease and preoperative serum creatinine levels of 1.8 mg/dL or more forms the basis of this report. Change in renal function was determined from glomerular filtration rates estimated from preoperative and postoperative serum creatinine. The influence of selected preoperative parameters and renal function response on time to dialysis and dialysis-free survival was determined by a proportional hazards regression model. RESULTS: In all, 83 patients underwent unilateral renal artery repair and 149 patients underwent bilateral repair, including repair to a solitary kidney in 17 cases. A total of 332 renal arteries were reconstructed, and 32 nephrectomies were performed in these patients. After surgery, there were 17 deaths (7.3%) in the hospital or within 30 days of surgery. Advanced patient age (P =.001; hazard ratio, 1.1; 95% CI [1.1, 1.2]) and congestive heart failure (P =.04; hazard ratio, 2.9 CI [1.0, 8.6]) demonstrated significant and independent associations with perioperative mortality. With a change of 20% or more in EGFR being considered significant, 58% of patients had improved renal function, including 27 patients removed from dialysis dependence; function was unchanged in 35% and worsened in 7%. Follow-up death from all causes or progression to dialysis dependence demonstrated a significant and independent association with early renal function response. Both patients whose function was unchanged (P =.005; hazard ratio, 6.0; CI [2.2, 16.6]) and patients whose function was worsened (P =.03; hazard ratio, 2.2; CI [1.1, 4. 5]) remained at increased risk of death or dialysis dependence. For patients with unchanged renal function after operation, risk of death or dialysis demonstrated a significant interaction with preoperative renal function. In addition to severe preoperative renal dysfunction, diabetes mellitus demonstrated a significant and independent association with follow-up death or dialysis. CONCLUSION: Surgical correction of atherosclerotic renovascular disease can retrieve excretory renal function in selected hypertensive patients with ischemic nephropathy. Patients with improved renal function had a significant and independent increase in dialysis-free survival in comparison with patients whose function was unchanged and patients whose function was worsened after operation. These results add further evidence in support of a prospective, randomized trial designed to define the value of renal artery intervention in patients with ischemic nephropathy.

Adult↗
PubMed1999

Surgery after failed percutaneous renal artery angioplasty.

PURPOSE: This retrospective review describes the surgical management of 51 patients after failed percutaneous renal artery angioplasty (F-PTRA). METHODS: From January 1987 through June 1998, 51 consecutive patients underwent surgical repair of either atherosclerotic (32 patients) or fibromuscular dysplastic (FMD; 19 patients) renovascular vascular disease after F-PTRA. These patients form the basis of this report. Surgical repair was performed for hypertension (29 patients with atherosclerosis: mean blood pressure, 205 +/- 34/110 +/- 23 mm Hg; 18 patients with FMD: mean blood pressure, 194 +/- 24/118 +/- 18 mm Hg) or ischemic nephropathy (20 patients with atherosclerosis: mean serum creatinine level, 2.0 +/- 0.8 mg/dL; three patients with FMD: mean serum creatinine level, 2.0 +/- 1.1 mg/dL). Emergency operation was required in four patients for acute renal artery thrombosis (one patient with atherosclerosis, one patient with FMD), renal artery rupture (one patient with atherosclerosis), or infected pseudoaneurysm (one patient with atherosclerosis). Operative management, blood pressure and renal function response to operation, and dialysis-free survival rate were examined and compared with 487 patients (441 patients with atherosclerosis, 46 patients with FMD) treated by operation alone. RESULTS: Among the patients with atherosclerotic renovascular disease, there were three postoperative deaths (9.4%) after repair for F-PTRA. Secondary operative repair was associated with emergent repair or nephrectomy in 16% of cases, while more extensive renal artery exposure and more complex operative management was required in 50% of patients with atherosclerosis and 65% of patients with FMD repaired electively. Among the 28 operative survivors with hypertension and atherosclerotic renovascular disease, blood pressure benefit after F-PTRA was significantly lower when compared with patients with atherosclerosis who underwent treatment with operation only (57% vs 89%; P <.001). However, blood pressure benefit in the 19 patients with FMD did not differ (89% vs 96%). Among the 28 patients with atherosclerosis, preoperative estimated glomerular filtration rate (EGFR) as compared with postoperative EGFR was significantly increased (47.4 +/- 4.2 mL/min/1.73m(2) vs 56. 6 +/- 5.1 mL/min/1.73m(2); P =.002). However, EGFR prior to PTRA was not significantly different from postoperative EGFR (51.6 +/- 3.4 mL/min/1.73m(2) vs 56.6 +/- 4.9 mL/min/1.73m(2); P =.121). As compared with patients with atherosclerosis who underwent treatment with operation alone, there was no difference in the dialysis-free survival rate. CONCLUSION: Operative repair after F-PTRA was altered in 59% of the patients with atherosclerosis and in 68% of patients with FMD. Blood pressure benefit for patients with FMD was unchanged after F-PTRA. However, the blood pressure benefit was significantly decreased among patients with atherosclerosis. Decreased EGFR after F-PTRA was recovered with operative renal artery repair. However, postoperative EGFR as compared with EGFR prior to PTRA was unchanged. Blood pressure and renal function response after F-PTRA for atherosclerotic renovascular disease warrants further study.

Adult↗
PubMed1999

Cryptococcal aortitis presenting as a ruptured mycotic abdominal aortic aneurysm.

Mycotic processes occasionally complicate atherosclerotic aortic disease and usually require aggressive surgical therapy to control sepsis and prevent arterial rupture. Rarely, fungal organisms are responsible for primary infection of the abdominal aorta. We report the first case of Cryptococcal aortitis presenting as a ruptured abdominal aortic aneurysm. The surgical, pathologic, and microbiologic aspects of fungal aortitis are discussed.

Aneurysm, Infected↗
PubMed1998

Duplex ultrasound scanning defines operative strategies for patients with limb-threatening ischemia.

PURPOSE: To characterize the accuracy of color-flow duplex ultrasound (DUS) in planning lower extremity revascularization procedures, we prospectively compared operations predicted by means of DUS arterial scanning (DUSAS) and operations predicted by means of conventional angiography (CA) with actual operations performed in 36 patients undergoing 40 vascular reconstructions for critical (grade II/III) lower extremity ischemia. METHODS: All patients were examined with lower extremity DUSAS followed by CA. DUSAS was performed from the aorta to the pedal vessels of the affected extremity. Adequacy of inflow was assessed, and the best distal target vessel with continuous, unobstructed flow was defined. An operative prediction was made and recorded based upon the DUSAS findings, and in a blinded fashion, based upon subsequent CA. The McNemar test for comparing correlated proportions was applied to test for the statistical significance of the difference (P < .05) between correct operations predicted by DUSAS and CA. RESULTS: Of the actual operations performed, 83% were correctly predicted by means of DUSAS (95% CI; range, 77% to 89%). Seven operations were incorrectly predicted with DUSAS. Of the actual operations performed, 90% were correctly predicted by means of CA (95% CI; range, 81% to 99%). Four operations were incorrectly predicted with CA. The McNemar test determined that the difference between correct operations predicted by means of DUSAS and correct operations predicted by means of CA was not statistically significant (P = .50). CONCLUSIONS: With few exceptions, DUSAS can be used to reliably predict infrainguinal reconstruction strategies. Vessels defined as adequate with DUSAS are rarely unfit for bypass. Prospective investigation of lower extremity revascularization based solely upon DUSAS is warranted.

Adult↗
PubMed1998

Infected renal artery pseudoaneurysm and mycotic aortic aneurysm after percutaneous transluminal renal artery angioplasty and stent placement in a patient with a solitary kidney.

Endovascular infections after percutaneous transluminal renal angioplasty with stenting (PTRAS) are rarely reported. Because strict longitudinal follow-up of patients undergoing PTRAS is lacking, the true incidence of such complications remains obscure. We report the first case of a patient with an infected renal artery pseudoaneurysm and de novo mycotic aortic aneurysm after PTRAS. This case serves to illustrate several important points, including (1) the retrieval of renal function in patients with renal artery occlusion, (2) the pathogenesis of infection after PTRAS, (3) the diagnosis and management of endovascular infection after percutaneous vascular intervention, and (4) recommendations for periprocedural antibiotic prophylaxis during PTRAS.

Aged↗
PubMed1998

Renal artery repair: consequence of operative failures.

OBJECTIVE: This report examines the blood pressure and renal function response in 20 consecutive patients after secondary renal revascularization following failed operative repair. SUMMARY BACKGROUND DATA: Most reports describing operative failure of renal artery (RA) repair emphasize the technical aspects of redo RA reconstruction and the immediate blood-pressure response to secondary operation. This report examines the eventual renal function and estimated survival after secondary intervention. METHODS: Primary methods of RA reconstruction, primary blood pressure and renal function responses, and causes of failed RA repair were defined for 20 patients requiring reoperation for recurrent hypertension or renal insufficiency. These parameters were compared with secondary procedures and eventual blood pressure and renal function response. The eventual outcome for these 20 patients was compared with 514 patients managed by primary renal revascularization during the same period. RESULTS: Failure of primary RA repair correlated with complex fibromuscular dysplasia requiring branch ex vivo reconstruction (p = 0.020). RA thrombosis frequently required nephrectomy (83%), whereas RA stenosis was successfully reconstructed (91 %; p = 0.001). Primary and secondary blood-pressure responses were equivalent (94% vs. 95% cured or improved); however, primary and eventual renal function responses differed significantly (p = 0.015), with seven patients dialysis-dependent on follow-up. Eventual dialysis dependence was associated with preoperative azotemia (p = 0.022), bilateral failure of primary RA repair (p = 0.007), and an increased risk of follow-up death (p = 0.002). Considering all 534 patients, failed RA repair demonstrated a significant and independent association with eventual dialysis dependence and decreased dialysis-free survival. CONCLUSIONS: Contemporary rates of reoperation after surgical RA repair are low. In properly selected patients, beneficial blood-pressure response is reliably observed after both primary and secondary operative procedures. However, secondary procedures are associated with a significant and independent risk of eventual dialysis dependence.

Adult↗
PubMed1997

Endovascular repair of peripheral aneurysms, pseudoaneurysms, and arteriovenous fistulas.

Endovascular repair of peripheral arterial lesions was performed in 10 patients including two iliac aneurysms, two iliac anastomotic pseudoaneurysms, one subclavian pseudoaneurysm, one axillary anastomotic disruption, two prosthetic pseudoaneurysms, and two posttraumatic arteriovenous (AV) fistulas. The indications for repair were aneurysm size in five cases, massive hematoma in one, threatened prosthetic dialysis graft in two, venous hypertension with non-healing ulcer in one, and arm pain in one. Vascular access was obtained through surgical cutdown in all cases, via the femoral artery in five patients, the proximal brachial artery in three and a prosthetic graft in two. Stented prosthetic grafts were used in five cases (1 polyester and polytetrafluoroethylene 4 [PTFE]), and PTFE-covered stents in five cases. Concomitant procedures were done in four patients including two open repairs of a common femoral artery aneurysm, a transluminal dilatation of a proximal aortic anastomotic stenosis, and an iliac artery transluminal angioplasty. Eight of 10 cases were technically successful. Completion arteriography revealed complete exclusion of all lesions, except for one minimal proximal stented graft leak in a pseudoaneurysm, and an incomplete obliteration of an AV fistula. No complications occurred. Operative time ranged from 45 min to 5 hours. Postoperative hospital stay was 1 day in five patients, 2 days in three patients, and 4 days in two patients. Follow-up contrast CT scan, arteriography, or duplex scanning demonstrated complete exclusion of all lesions except an AV fistula, and decrease in size in three aneurysms. The proximal leak initially present in a stented graft resolved. All grafts and covered stents remained patent at 2-19 months of followup. Endovascular exclusion of peripheral arterial aneurysms, pseudoaneurysms, and AV fistulas can be done with a high degree of technical success, low morbidity, and short hospital stay. Short-term follow up is encouraging, however, long term follow up of these procedures is warranted to assess durability of the repair and absence of complications.

Aged↗
PubMed1997

Innominate artery occlusive disease: management with central reconstructive techniques.

BACKGROUND: The purpose of this study was to review our experience with central vascular reconstruction for innominate artery occlusive disease. Eighteen patients underwent central reconstruction for innominate artery (IA) occlusive disease during an 8-year period (1986 to 1994). Mean age was 59 years (range, 36 to 77 years). Women outnumbered men 12 to 6. All patients had symptoms including amaurosis fugax 55%, transient ischemic attacks 44%, vertebrobasilar insufficiency 44%, and arm claudication 33%. The IA was occluded in three patients and stenotic in 15. Three patients underwent previous extrathoracic bypass procedures for IA lesions that failed. METHODS: Operations performed through a median sternotomy included aortocarotid bypass with reimplantation of the subclavian (n = 10) and aortoinnominate bypass (n = 7). Transection and oversewing of the IA was performed in all but one patient, in whom ligation of the IA was performed. One patient with severe chronic obstructive pulmonary disease and previous coronary artery bypass grafting underwent retrograde-transluminal IA angioplasty with endovascular stent placement via a carotid approach. Four patients underwent concomitant carotid endarterectomy). Two patients underwent concomitant coronary artery bypass grafting at the time of IA reconstruction. RESULTS: There was one operative death from myocardial infarction. Perioperative morbidity included dysrrhythmia (three), respiratory insufficiency (three), subendocardial myocardial infarction (two), cerebrovascular accident with complete recovery (two), hemorrhage (one), and acute graft occlusion (one). All grafts remained patient at a mean follow-up of 21 months (range, 8 to 60 months). The only patient who underwent ligation of the IA required a subsequent revision of the IA to transection and oversewing for an embolic event at 4 months status-post aortocarotid bypass. The patient who underwent angioplasty remained asymptomatic with a patient IA at 12 months. Average length of stay for transthoracic repair was 14 days and for transluminal angioplasty 2 days. CONCLUSIONS: Innominate artery bypass based on the ascending aorta is effective in providing relief of symptoms and has a high patency rate. Because of the significant morbidity, these procedures should be reserved for patients with symptoms. The IA should be transected and oversewn to prevent recurrent embolism. Transcarotid, retrograde angioplasty provides an alternative approach to stenotic lesions located in the IA or proximal common carotid artery. An aggressive approach directed at defining coronary artery disease is an invaluable adjunct to the proper treatment of this patient population.

Adult↗
PubMed1996

Management and outcome of chronic atherosclerotic infrarenal aortic occlusion.

PURPOSE: To evaluate the management and outcome of chronic atherosclerotic infrarenal aortic occlusion (IRAO), a review of 48 patients who were treated for angiographically documented IRAO between January 1980 and December 1994 was undertaken. Mean follow-up was 45 months. Mean age was 57 years (range, 33 to 88 years). Forty-seven patients were heavy smokers. Symptoms included claudication in 81%, rest pain in 25%, and tissue loss in 15%. Impotence was documented in 73% of men. Associated arterial disease included inferior mesenteric artery occlusion in 31 patients, renal artery stenosis or occlusion in 12, superior mesenteric artery stenosis in two, and celiac artery stenosis in one. METHODS: Forty inflow procedures were performed, including 17 thoracobifemoral bypass (TBF) procedures, 15 aortobifemoral/iliac bypass (ABFI) procedures, and eight axillobifemoral bypass (AXBF) procedures. Eight patients were managed without surgery. The thoracic aorta was chosen as the inflow source in 17 patients because of previous abdominal aortic surgery in eight, poor status of the abdominal aorta in eight, and horseshoe kidney in one. RESULTS: The overall operative mortality rate was 5%, and the perioperative morbidity rate was 18%. There was no statistical difference in perioperative mortality and morbidity rates among the operative groups. The five-year survival rate (life-table) for all IRAO patients was 67%. TBF and ABFI revascularization procedures yielded 5-year patency rates of 71% and 79%, respectively (p < 0.05). All eight patients who underwent AXBF died or had occluded grafts at 3 years after surgery. Two-year patency rates (life-table) for TBF, ABFI, and AXBF were 92%, 92%, and 44%, respectively. The AXBF patency rate was significantly inferior to those of TBF and ABFI (p < 0.05). Changes in ankle-brachial indexes after TBF or ABFI were similar, but were significantly greater than changes after AXBF (p < 0.05). Three patients in the nonoperative group died, and two underwent major amputation. Acute renal failure did not occur in our study population. Follow-up creatinine levels > 2.0 mg/dl were documented in three operative patients and in one nonoperative patient, and none required dialysis. CONCLUSIONS: In patients who have IRAO, aorta-based inflow procedures are superior to AXBF both in hemodynamic outcome and in patency rates. Treatment of IRAO with TBF or ABFI yields similar long-term results; the descending thoracic aorta represents an excellent inflow alternative to the abdominal aorta. Clinically significant renal impairment is rarely associated with IRAO. Nonoperative management of IRAO is associated with an increased mortality rate and a high rate of limb loss.

Adult↗
PubMed1996

Pulsatile perfusion system for ex vivo investigation of biochemical pathways in intact vascular tissue.

We have constructed and performed initial validation of an innovative perfusion system that allows exposure of intact segments of vascular tissue to realistic physiological and hemodynamic environments ex vivo. Computer-controlled opening and closing of an in-line gate valve allows generation of arterial pressure waveforms. The control algorithm predicted resultant pressure waveforms with a high degree of accuracy (Pearson correlation coefficient > 0.97). To document vascular homeostasis ex vivo, vasomotor bioassays and morphological studies were performed. The bioassays consisted of injecting epinephrine (2 x 10(-3) mg/ml) into the perfusion system followed by acetylcholine (100 microM) while concurrently measuring vessel diameter with a laser micrometer, significant vasomotion was measured for canine carotid arteries (n = 4) bioassayed after 1, 24, and 48 h of perfusion (P < 0.03). Additionally, human saphenous vein segments were perfused for 24 h (n = 4) and viewed with laser confocal scanning microscopy and transmission electron microscopy; photomicrographs show typical vascular morphology. We conclude that the vascular perfusion system described herein is well suited for investigating the response of intact vascular tissue to hemodynamic variables.

Acetylcholine↗
PubMed1995

An aortic aneurysm model for the evaluation of endovascular exclusion prostheses.

PURPOSE: The purpose of this study was to develop an aortic aneurysm (AA) model with a predictable tendency for rupture for the evaluation of the efficacy of endovascular prostheses in preventing rupture and their long-term outcome after implantation. METHODS: An infrarenal AA measuring two to three times the diameter of the proximal aorta was created in 18 dogs with a full-thickness patch of jejunum. Seven dogs were allowed to survive without aneurysm exclusion. In 11 dogs the aneurysm was immediately excluded with a stented 8 mm Dacron graft mounted in a 14F delivery system introduced through the femoral artery with aortographic guidance. The pressure differential between the aorta and the excluded aneurysm was measured, and angiography, necropsy, and histologic examination were performed at 3- and 6-month survival. RESULTS: All animals survived aneurysm implantation. Without aneurysm exclusion, six dogs died of rupture within 1 to 6 days of surgery. In three dogs the exclusion failed because of graft-to-aorta size mismatch or misplacement demonstrated on angiography and by a low pressure differential between the aorta and the aneurysm (< 5 mm Hg); all three dogs died of rupture within 4 days. In eight dogs the aneurysm was successfully excluded on the basis of angiography results, with a mean aorta-to-aneurysm pressure differential of 51 mm Hg. Two dogs were killed at 1 and 6 days after surgery because of paraplegia produced by graft thrombosis because of kinking but without evidence of aneurysm rupture. Six dogs survived on a long-term basis, and angiography and necropsy performed at 3 and 6 months revealed patent grafts without migration, reduction in aneurysm size, no flow in the excluded lumbar arteries in five of six animals, and complete incorporation of Dacron graft and stents. No evidence of graft infection was found in any animal. The survival rate was significantly better (p < 0.023) in dogs with successfully excluded aneurysms (n = 6) compared with that in dogs without exclusion or with failed aneurysm exclusion (n = 7). CONCLUSION: This aneurysm model demonstrates that without effective aneurysm exclusion all animals die of rupture and that successfully placed endovascular prostheses can prevent AA rupture with long-term graft patency and stability. Endovascular aortic Dacron grafts in dogs undergo complete incorporation at 3 months from implantation. This aneurysm model is useful for the evaluation of endovascular devices designed for the treatment of AAs.

Animals↗
PubMed1992

Evaluation of endothelium-derived nitric oxide mediated vasodilation utilizing ex vivo perfusion of an intact vessel.

The traditional evaluation of the endothelium-derived nitric oxide (EDNO) pathway involves isolated aortic rings with attached strain gauges. This model is nonphysiologic and does not permit studies lasting longer than several hours. Our objective was to overcome the limitations of these "traditional" methods utilizing a physiologic, whole vessel model as a reproducible assay of EDNO. Canine carotid arteries (n = 4) were removed (maintaining in vivo arterial geometry), mounted in a specially designed, continuous-flow circuit, and perfused at 100 ml/min, 80 mm Hg with Medium-199/10% canine serum. Physiologic pH, pCO2, pO2, and temperature were precisely regulated. A non-contacting, helium-neon laser micrometer was interfaced with the current system to provide continuous measurement of vessel external diameter and to quantitate changes in vessel wall geometry in response to epinephrine (EPI; 2 x 10(-5) to 2 x 10(-3) mg/ml) and acetylcholine (ACh; 0.1 to 100 microM) challenge. Further characterization of the perfusion system included the use of a competitive inhibitor to EDNO production, NG-monomethyl-L-arginine (L-NMMA), and the effect of this compound on ACh-induced vasodilation. The reversibility of this blockade was verified via the sequential addition of L-arginine (L-ARG; 0 to 3 mM). Data are expressed as the ratio of steady-state vessel cross-sectional area (CSA) following administration of vasoactive substance to the CSA prior to vasoactive challenge. Our results indicate that EPI and ACh produced significant dose-dependent vasoconstrictive and vasodilatory responses, respectively (P less than 0.001, ANOVA).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1987

Analysis of donor criteria for the prediction of outcome in clinical liver transplantation.

The results of 219 orthotopic human liver transplants performed during 1985 at the University of Pittsburgh were reviewed to determine whether donor parameters could be used to predict the quality of early graft function. Multivariate discriminant analysis demonstrated that traditional parameters of donor assessment are unreliable predictors of poor graft function. Furthermore, 56% of the donors considered poor by conservative selection criteria produced livers with good early posttransplant function. Survival of recipients of primary allografts from donors rated poor was no different than survival of recipients of allografts from donors rated good.

Adolescent↗
PubMedDate not supplied

Modulation of myofibroblast proliferation by vascular prosthesis biomechanics.

Cyclic deformation in vitro modulates smooth muscle cell proliferation. Different degrees of cell deformation occur in vivo on grafts of different compliance. This study evaluates the influence of prosthetic biomechanics on cell proliferation. Two types of composite 80% bioresorbable PG910/20% polypropylene (PP) aortic grafts differing only in the elasticity of the PP were implanted into rabbits. After PG910 resorption, prosthetic biomechanics were determined by PP (% elongation: Group 1, 101 +/- 6 versus Group 2, 63 +/- 4). Killing was performed at 1, 2, 3, and 6 months, and patency, dynamic compliance, mitotic index (MI), and inner capsule thickness (ICT) were determined. Initially all parameters were identical. After PG910 resorption (1-2 months), significant differences were seen. At late analysis, Group 1 MI was significantly greater than Group 2 (3 months: 4.67 +/- 2.5 versus 3.11 +/- 2.5 [p < 0.02]; 6 months: 4.11 +/- 2.3 versus 2.67 +/- 0.9 [p < 0.005]). Inner capsule thickness in Group 1 was also significantly greater than Group 2 (3 months: 219 +/- 20 versus 129 +/- 40 [p < 0.05]; 6 months: 220 +/- 50 versus 130 +/- 40 [p < 0.05]). Dynamic compliance differed at 2 months (p = 0.057). Patency was worse in Group 1 (p = NS). In vivo cellular proliferative activity is directly related to mural cyclic deformation induced by altered biomechanical graft characteristics.

Anastomosis, Surgical↗