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Biomedical subjects

J A DeWeese

Publications and source records attributed to J A DeWeese.

At least 19 recordsLinked to original sources
PubMed1992

Peroneal artery bypass: a multifactorial analysis.

Sixty-two bypass grafts to the peroneal artery were performed at the University of Rochester Medical Center between 1984 and 1990. An autogenous conduit was used in 45 patients and a prosthetic conduit in 17 patients. Primary cumulative patency rates were 49% at two years and 30% at four years following operation. Limb salvage was achieved in 68% of patients. The two year cumulative patency rate was significantly better when the peroneal artery was of good quality arteriographically compared with those in which stenoses were present (75% versus 25%, p less than 0.05); in patients without inflow disease compared with patients with inflow disease (56% versus 11%, p less than 0.05); and in saphenous vein grafts compared with prosthetic grafts (55% versus 17%, p less than 0.05). The factors that did not influence patency were the presence of a direct peroneal collateral vessel filling a pedal vessel, age, sex, diabetes, and the size of the peroneal artery. The results of peroneal artery bypass in end-stage patients are dependent on the presence of adequate autogenous vein and a recipient peroneal vessel free of disease. Under these circumstances, the results of the procedure approach that of standard femorotibial reconstruction.

Aged↗
PubMed1992

An evaluation of new methods of expressing aortic aneurysm size: relationship to rupture.

The diameter of aortic aneurysms were standardized to measures of patient size and normal aortic size in an effort to define indexes that might be more predictive of aneurysm rupture than raw aneurysm diameter alone. Normal aortic diameters were measured in 100 patients undergoing abdominal CT scans for other reasons, and an average infrarenal aortic diameter of 2.10 +/- 0.05 cm was observed. Normal aortic diameter was dependent on both age and sex, ranging from 1.71 +/- 0.06 cm in women below age 40 years to 2.85 +/- 0.04 cm in men above age 70 years. Overall, 11 (5.1%) of the ruptures occurred in aneurysms less than 5 cm in diameter, and four (1.9%) occurred in aneurysms less than 4.0 cm in diameter. When the CT scans of 100 patients undergoing elective aneurysm resection were compared with those of 36 patients with ruptured aneurysms, no threshold diameter value accurately discriminated between the two groups. However, standardization of the aneurysm diameter to the transverse diameter of the third lumbar vertebral body as an index of patient body size produced an accurate predictor of rupture when a threshold ratio of 1.0 was used. No aneurysm ruptured below this ratio, but 29% of elective aneurysms were smaller than the vertebral body diameter. Receiver operating characteristic curve analysis confirmed the superiority of the aneurysm to vertebral body diameter ratio as a discriminator of ruptured aneurysms. It appears that aneurysm diameter alone is not sufficiently predictive of rupture to be used as the sole indication for elective resection.

Adult↗
PubMed1992

Vascular disease in the antiphospholipid syndrome: a comparison with the patient population with atherosclerosis.

The antiphospholipid syndrome was diagnosed in 19 of 1078 patients treated between 1987 and 1991. All patients with antiphospholipid syndrome had either anticardiolipin antibody (16/19) or lupus anticoagulant (10/19); three patients had thrombocytopenia, eight patients had a prolonged partial thromboplastin time, and 10 patients had an elevated erythrocyte sedimentation rate. The most common site of involvement was the cerebral circulation (nine patients), manifested by transient ischemic attacks or stroke. Eight patients had upper extremity disease, characterized by symptoms of Raynaud's phenomenon, with angiographic lesions involving the brachial, radial, ulnar, and/or digital arteries. Lower extremity disease occurred in seven patients, with clinical presentations similar to those of atherosclerosis and varying angiographic patterns. In comparison with the population having atherosclerosis, patients with arterial manifestations of antiphospholipid syndrome were more likely to be women (13 of 19 versus 411 of 1078, p less than 0.02), were significantly younger (46.2 years versus 63.6 years, p less than 0.0001), did not smoke (1 of 19 patients versus 700 of 1078, p less than 0.0001), had a higher percentage of upper extremity involvement (8 of 18 versus 13 of 1078, p less than 0.0001), and had a higher incidence of early graft failure (9 of 12 grafts versus 13 of 371 grafts, p less than 0.0001). The syndrome is associated with the repetitive failure of vascular reconstructions and occlusion of native vessels. Antiphospholipid syndrome should therefore be suspected in young, female, nonsmokers with vascular disease, especially those with involvement of the upper extremity, cerebrovascular disease with normal findings on extracranial carotid angiography, and premature graft failure.

Adult↗
PubMed1992

Natural history of recurrent and residual stenosis after carotid endarterectomy: implications for postoperative surveillance and surgical management.

BACKGROUND: Noninvasive surveillance of patients after carotid endarterectomy is practiced routinely to detect recurrent stenoses. Many authors advocate repair of asymptomatic severe stenoses so detected. The likelihood of these lesions causing neurologic symptoms is unknown. Our aims were to (1) define the incidence of lesions, (2) determine the frequency of associated neurologic symptoms, and (3) identify patient-dependent factors that might predict restenosis. METHODS: Data on the status of 449 carotid arteries after endarterectomy were reviewed. The number of recurrent and residual severe (greater than or equal to 80%) stenoses was identified. Interval to development of symptoms was determined by life-table analysis. Patient-dependent factors (age, gender, smoking, diabetes, and patch closure) were evaluated by univariate and multivariate analysis to identify possible associations with severe lesions. RESULTS: Severe (greater than or equal to 80%) stenoses were seen in 35 patients (7.9%). Residual lesions were seen in 17 cases (eight occlusions and nine stenoses); recurrent lesions were identified in 18 patients (3.9%). Symptoms developed in five cases (14%) (one residual and four recurrent) 35, 48, 68, 98, and 103 months after surgery. The likelihood of developing symptoms associated with stenosis at 5 years was 6%. No factors correlated with residual stenosis. Age less than 60 years, female gender, primary closure, and absence of diabetes were more common in patients with recurrent lesions. CONCLUSIONS: Severe lesions can be found after carotid endarterectomy in at least 8% of patients and consist of residual defects, as well as recurrent stenoses. Recurrent lesions are more common in specific patient subgroups. These lesions are stable for long periods and the majority remain asymptomatic. Operation is not indicated unless symptoms develop in these patients. Intraoperative completion evaluation may be indicated to reduce the incidence of residual disease. Early noninvasive evaluation is useful as a quality-control measure. Repeated surveillance may provide data on the course of restenosis or contralateral disease progression but is of limited clinical benefit.

Analysis of Variance↗
PubMed1991

Treatment of aortic coarctation by axillofemoral bypass grafting in the high-risk patient.

Operative correction of coarctation of the aorta has been performed for 45 years. Reoperation for recurrent coarctation is necessary in as many as 5% to 10% of patients. Repair of recurrent coarctation carries an operative mortality of between 5% and 10%. Coarctation repair involves an increased risk in patients with advanced age, recurrent coarctation, congestive heart failure, and pulmonary disease. We report 3 cases where axillofemoral bypass has been used to treat high-risk patients with aortic coarctation. Two patients had had previous coarctation repair in addition to serious medical problems. Another patient had suffered three myocardial infarctions and had disabling congestive heart failure. All patients had an immediate marked decrease in their preoperative peak systolic pressure gradient across the coarctation. Systemic hypertension and symptoms of congestive heart failure were improved in all patients. The length of follow-up was 15 months, 8.5 years, and 10.5 years. Reassessment with noninvasive vascular segmental pressure studies with and without an exercise component showed no recurrence of the pressure gradient. This procedure should be considered when treating coarctation of the aorta in the high-risk adult.

Aged↗
PubMed1991

Freezing preservation of adult mammalian heart at high subzero temperatures.

The present study adapted the overwintering strategy employed by freeze-tolerant amphibians and reptiles to freeze-preserve the isolated rat heart. The heart was flushed with a cardioplegic solution and supercooled to -1.2 and -3 degrees C. Then freezing was induced by inoculation of ice crystal. The viability of the heart explant was assessed after reanimation by the isolated working heart perfusion. There was no recovery of function in hearts flushed with solution containing 0.28 mM CaCl2. Lowering the concentration of CaCl2 to 0.15 mM, however, rendered good functional return. Furthermore, inclusion of 50 mM glycerol in the flush solution dramatically improved functional preservation. Under the best conditions defined here, the recoveries of aortic flow, coronary flow, cardiac output, systolic pressure, and work in hearts stored at -1.2 degrees C for 3 h were 72.8 +/- 6.8, 87.2 +/- 4.2, 77.6 +/- 5.4, 83.4 +/- 2.8, and 66.6 +/- 5.9% (mean +/- SEM, n = 8) of the unstored control levels, respectively. The myocardial ice content was 18.6 +/- 5.4% (n = 5) of tissue water. Prolonging the storage time to 5 h increased the ice content to 45.3 +/- 8.1% and reduced the recovery of cardiac output to 23 +/- 11% of the control value (mean +/- SEM, n = 5). Hearts frozen at -3 degrees C for 1.5 h showed 29.4 +/- 8.7% (n = 3) of control cardiac output during reperfusion. This novel approach may provide an opportunity to advance our knowledge about freezing preservation of not only the heart but other solid organs as well.

Animals↗
PubMed1991

The clinical course of residual carotid arterial disease.

Over a 5-year period 642 patients underwent 686 carotid endarterectomies with patch closure and intraoperative surveillance with continuous-wave Doppler. The perioperative stroke rate was 1.5%. Patients were screened with duplex scans immediately after operation for the presence of residual carotid lesions, and followed every 3 to 6 months for either the development of a true recurrent lesion or a change in a residual one. Five hundred thirty-nine arteries (84%) had no postoperative abnormalities. The incidence of recurrent carotid lesions in this groups was 1.5%, 3.4%, and 5.2% at 1, 2, and 3 years, respectively. The incidence of symptoms in this group was 0.2%, 0.7%, and 1.4% at 1, 2, and 3 years, respectively. The earliest recurrence or symptom occurred 8 months from operation. One hundred forty-seven arteries had residual lesions that were more common when either a temporary shunt was used or the operation was carried out above the hypoglossal nerve or below the omohyoid muscle. Sixty-one patients who had plaque proximal to the arteriotomy without a significant stenosis were followed an average of 21 months. There were no changes in plaque morphology and no proven symptoms related to the residual lesion. Fifty-six patients with both plaque and significant hemodynamic abnormalities in the carotid bulb were followed an average of 18 months. Seven of these patients (12.5%) had either a significant deterioration of the lesion or a symptom from it. Each event occurred within 6 months of operation. Thirty patients had significant flow abnormalities but no visible plaque. None of these lesions deteriorated. Although common, residual carotid lesions are benign unless the lesion is characterized by both plaque within the artery and a hemodynamically significant stenosis. These lesions should be further investigated and treated when discovered.

Arteriosclerosis↗
PubMed1991

Popliteal artery aneurysms: a 25-year surgical experience.

Operative repair was undertaken for 51 popliteal aneurysms in 39 patients between 1958 and 1990. Operation was performed on an emergency basis in 19 extremities with limb-threatening ischemia and as an elective procedure in 32 extremities. Cumulative limb salvage (94%) rates and patency rates (67%) became significantly different at 6 years (p less than 0.05). Graft patency was affected by clinical presentation and runoff. After 1 year, cumulative patency for extremities with limb-threatening ischemia was significantly lower than for those having an elective operation (69% vs 100%, p less than 0.05). Runoff did not influence graft patency until 3 years, at which time cumulative patency was better in extremities with good runoff than in extremities with poor runoff (89% vs 30%, p less than 0.05). Limb salvage was affected only by presentation. All limb loss (three patients) occurred within the first month in extremities with graft occlusion after operation for limb-threatening ischemia. Runoff did not influence patency rates for extremities with limb-threatening ischemia, since no difference was observed in runoff between the two groups. We conclude that elective repair is indicated in all patients with popliteal aneurysms. It is associated with little risk to the patient, and prevents the need for operation in the setting of limb-threatening ischemia with its poorer overall results and definite incidence of amputation.

Aged↗
PubMed1990

Optimal osmolality for cold storage of the cardiac explant.

Cell swelling is a major problem of cardiac preservation. This study evaluated the effect of storage solution osmolality on long-term preservation of cardiac function. Isolated rat hearts were flushed and stored in solutions of 260 to 350 mOsm/kg water at 0 degrees C for 9 hr. Cardiac performance was assessed using the isolated working heart reperfusion. Function of fresh unstored hearts served as the control. The stored hearts had normal heart rate after reperfusion. Other hemodynamic functions recovered to various levels of the control value and showed biphasic responses to solution osmolality. Hearts stored in hyposmotic (260 and 270 mOsm) and hyperosmotic (310, 330, and 350 mOsm) solutions performed poorly. Those stored in 280 to 290 mOsm solutions showed superior recovery in cardiac function. Among all parameters, coronary flow correlated linearly with aortic flow, cardiac output, systolic pressure, work, oxygen consumption, and coronary vascular resistance. Solutions of 280, 290, and 310 mOsm caused 6 to 9% increases in tissue water (TW) over the control hearts during 9 hr storage, whereas 350 mOsm solution maintained TW at the control level. After reperfusion, all stored hearts gained water (25 to 38%) compared to hearts with no reperfusion. Postreperfusion myocardial ATP content was only 70-79% of control level and did not correlate to function recovery. In conclusion, (1) the optimal osmolality of our preservation fluid is 280 to 290 mOsm and moderate or severe hyperosmolality is detrimental to cardiac function, and (2) preservation of coronary function may be crucial to future improvement of storage solution.

Adenine Nucleotides↗
PubMed1990

Fate of the exposed saphenous vein graft.

Patients with functioning vein grafts may present with wound problems resulting in exposure of the graft. We reviewed the courses of 16 patients presenting with this problem to determine the causative factors and the most appropriate management of this therapeutic dilemma. Diabetes mellitus (11 of 16, 68.7%) and wound infection (12 of 16, 75%) were frequent pre-existing conditions associated with exposed venous grafts. All patients with exposed vein grafts were initially treated conservatively with regular application of moist sterile dressings, followed by split-thickness skin graft coverage of the wounds when clean. The wounds healed in 7 patients, whereas 9 patients developed complications of hemorrhage (7 patients) and graft thrombosis (2 patients). The outcome of therapy was highly dependent on the type of organism originally cultured from the wounds. The incidence of vein graft disruption was lowest when the wounds were sterile (25%) or when gram-positive bacteria grew (25%). Gram-negative infection uniformly resulted in disruption of the exposed venous graft. When a new graft was placed, the secondary graft became reinfected in all patients with gram-negative primary graft infection. There were no instances of secondary graft reinfection when gram-negative bacteria were not present. These data suggest that the outcome of patients presenting with exposed vein grafts is highly dependent on the bacterial flora of the process. Vein graft disruption is frequent in patients with gram-negative infection, suggesting that these patients should be treated with distant graft ligation and extra-anatomic bypass. By contrast, patients without gram-negative infection may be successfully managed with local wound care.

Adult↗
PubMed1990

Differential effects of a gram-negative and a gram-positive infection on autogenous and prosthetic grafts.

A canine model was developed to study the differential response of a gram-negative and a gram-positive bacterial infection on autogenous and prosthetic grafts. After replacing segments of the femoral arteries of 15 dogs with autogenous vein in one groin and polytetrafluoroethylene in the contralateral groin, 10(8) colony-forming units of nonmucin-producing Staphylococcus epidermidis (five dogs), Pseudomonas aeruginosa (five dogs), or sterile saline solution (five dogs) were directly inoculated onto the grafts. The grafts were examined 7 to 10 days after implantation. None of the control dogs exhibited inflammatory signs, and no grafts or anastomoses disrupted. S. epidermidis was unrecoverable from either graft material in any of the animals, although histologic evaluation confirmed neutrophils and bacteria in four of five animals in the vein and polytetrafluoroethylene groups. No dog inoculated with S. epidermidis had graft or anastomotic disruption. By contrast, P. aeruginosa was recovered from both types of grafts in all inoculated animals. Neutrophils, bacteria, and microabscesses were observed in all of these animals. In addition, three of five polytetrafluoroethylene grafts and all five vein grafts disrupted either at the anastomoses or in the body of the vein graft. Therefore S. epidermidis is a less virulent organism that may persist in graft walls despite negative cultures, whereas P. aeruginosa is a highly virulent organism that can disrupt native artery, vein grafts, and anastomoses. The graft material appears to be less important than the bacteria in determining the outcome of infection.

Animals↗
PubMed1990

Factors determining survival after ruptured aortic aneurysm: the hospital, the surgeon, and the patient.

The 10-year experience of a single community was reviewed and a multivariate analysis was performed to determine the relative importance of clinical and environmental factors in mortality after ruptured abdominal aortic aneurysm resection. Ruptured aneurysms were repaired in 243 patients in six area hospitals (one university, five community) by 25 surgeons (16 vascular, 9 general). Overall, 30-day mortality was 55% (133/243). Although the mortality by hospital ranged from 44% to 68%, these differences were not statistically significant. However, significant variations occurred in the mortality rates of individual surgeons, ranging from 44% to 73%. The mortality rate for the vascular surgeons was less than that of the general surgeons, 51% versus 69% (p less than 0.05). Clinical factors were evaluated, and the most significant parameters were systolic blood pressure, presence of chronic obstructive lung disease, and history of chronic renal insufficiency. These results support the implication that the degree of specialization of the surgeon and the preexisting health of the patient are the most important determinants of survival after ruptured abdominal aortic aneurysm. The size and sophistication of the hospital appear to be less influential factors.

Aged↗
PubMed1990

Comparison of infrainguinal graft surveillance techniques.

One hundred seventy-seven patients with infrainguinal bypass grafts were followed by use of standard graft surveillance techniques to learn more about the natural history of hemodynamic abnormalities in the patient with no symptoms. A decrease in the ankle/brachial pressure ratio of 10% or more was considered an abnormal evaluation. Results of the duplex scan were interpreted as abnormal when the peak systolic flow velocity was greater than 120 cm/sec or less than 40 cm/sec. There were 18 graft thromboses (10%) during the period of observation, and nine of these grafts were successfully revised or replaced. Recurrent symptoms prompted graft revision in 20 additional patients, and 18 of these reoperations were successful. Twenty-nine of the 38 reoperations occurred within the first 18 months of the study. The primary cumulative patency rate was 86% at 1 year and 66% at 5 years. The secondary cumulative patency rate was 91% at 1 year and 80% at 5 years. Sudden graft occlusion occurred in five patients after a normal ankle/brachial index. Most of 90 patients with abnormal ankle/brachial indexes reverted to normal at the next visit. Nineteen of the 26 that did not, had significant graft problems, but only eight patients had operable conditions, and five of the eight already had occluded grafts. No patient with a normal ankle/brachial index and duplex scan results had graft occlusion before their next surveillance visit. If the duplex scan outcome was abnormal but the ankle/branchial index normal the incidence of sudden graft occlusion was 4%. In contrast, if the duplex scan outcome was abnormal and the ankle/brachial index is reduced, then the risk of graft occlusion is 66%.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Vessel Prosthesis↗
PubMed1989

Assessing risk associated with carotid endarterectomy. A statement for health professionals by an Ad Hoc Committee on Carotid Surgery Standards of the Stroke Council, American Heart Association.

This position statement provides guidelines for assessing risk associated with carotid endarterectomy and defines the point at which risk is too high to perform surgery for specific indications described below. Morbidity and mortality levels are discussed. This statement does not address indications for surgery or merits of specific medical or surgical treatments. Results of current studies that compare relative risk of various treatments for carotid artery disease are not yet available.

Brain Ischemia↗
PubMed1989

Results of supraceliac aortic clamping in the difficult elective resection of infrarenal abdominal aortic aneurysm.

We have used clamping of the aorta above the celiac axis (SC) in 30 of 431 elective resections of infrainguinal abdominal aortic aneurysms (AAA) during the past five years as an alternative to a difficult aortic cuff dissection. The results of SC clamping in these 30 patients are compared with the results of 379 routine aneurysm resections with infrarenal (IR) clamping and 22 additional aneurysm resections where the clamp was placed immediately above the renal arteries. These difficult cuff dissections occurred in 12 patients with inflammatory AAA, in 11 patients with juxtarenal AAA, and in seven patients with recurrent or noninfected false AAA of the proximal cuff. Patients with ruptured or suprarenal aneurysms and those undergoing combined operation for a visceral ischemic syndrome and an aneurysm were excluded from this study. Patients with SC clamping had similar operative mortality rates, comparable renal function, and frequency of cardiac events as patients with IR clamping. Blood loss was slightly higher in the SC group (p = 0.07) and serum aspartate amino transferase (AST) levels were three times higher than in the IR group; however, this was of no clinical significance. In contrast, those 22 patients whose aortas were clamped immediately above the renal arteries (AR) had higher perioperative mortality rates (2% IR, 3% SC vs 32% AR) and a higher incidence of kidney failure requiring dialysis (1% IR, 3% SC vs 23% AR). The mean values of serum creatinine and blood urea nitrogen were also significantly higher in the AR group when compared with both the IR and the SC groups (IR: 25 and 1.5 mg/dl, respectively; SC: 27 and 1.8 mg/dl; AR: 41 and 3.5 mg/dl). The single most important risk factor accounting for the differences between clamping above the celiac artery and clamping above the renal arteries was the presence of atherosclerotic debris in the nonaneurysmal, juxtarenal aortic segment. Clamping the aorta with juxtarenal atherosclerosis caused either atheroembolization to kidneys, legs, and intestine or injury to the aorta, renal arteries, or both; it was the cause of morbidity in all five cases of kidney failure requiring dialysis and accounted for all seven of the deaths in the AR group. SC clamping does not add risk to the patient undergoing resection of an infrarenal AAA and is the preferred method of achieving proximal control of the infrarenal aorta when a a hazardous cuff dissection is likely.(ABSTRACT TRUNCATED AT 400 WORDS)

Aorta, Abdominal↗
PubMed1989

Spinal cord ischemia: an evaluation of pharmacologic agents in minimizing paraplegia after aortic occlusion.

Superoxide dismutase (SOD), barbiturates, and hypothermic crystalloid were evaluated for their effectiveness in minimizing ischemic damage to the spinal cord at 40 minutes of aortic occlusion. Forty-two dogs underwent proximal and distal thoracic aortic occlusion for 40 minutes with infusion of test agents into the occluded segment. The dogs were divided into six groups. Group 1 (n = 6) served as control. Group 2 (n = 6) received hypothermic crystalloid. Group 3 (n = 6) animals received thiopental. Group 4 (n = 7) received SOD. Group 5 (n = 9) received hypothermic crystalloid and thiopental. Group 6 (n = 8) received hypothermic crystalloid, thiopental and SOD. The animals were observed for neurologic deficit for 72 hours. In group 1, six of six dogs showed complete paralysis. Five of six dogs from group 2, five of six dogs from group 3, and five of seven dogs from group 4 showed complete paraplegia. The remaining dogs in these groups showed varying degrees of recovery. Four of nine dogs in group 5 had complete paraplegia, three dogs showed varying degrees of recovery, and two dogs had no neurologic deficit. In group 6, one dog had complete paraplegia, three had partial recovery, and four had no neurologic deficit. Group 6 was the only group that showed significantly less late neurologic impairment than the control group. We concluded that although cold perfusion, barbiturates, and SOD are not protective when used alone, they are effective when all are used in combination. The combination of cold perfusion, barbiturates, and SOD significantly decreases neurologic deficit after 40 minutes of aortic occlusion.

Animals↗